From the outside, the new 15-inchers don't have much new to meet the eye. The new models sport the same solid aluminum enclosure with the indented thumb scoop for opening the lid. There's the same huge touchpad that responds to the familiar range of finger gestures, and the same relatively stiff button that makes it easier to tap and swipe the touchpad with your fingers than to actually depress the button. There's still the big glossy screen, which you either love or love to hate, with the same resolution of 1,440 by 900 pixels. All ports are still grouped together on the left side of the case, including the MagSafe power port, Gigabit Ethernet, FireWire 800, two USB ports, and separate audio in and out ports. The iSight camera is positioned in the same spot, as is the 8x SuperDrive. Despite these familiar features, Apple has applied significant changes to the 15-inch models.

No ExpressCard/34 slot. Replacing this flexible hardware receptacle for eSATA cards, network cards, TV tuner cards, and more, is something new--a Secure Digital (SD) card slot that you can use not only to transfer files to your Mac, but also to boot the laptop. The SD card slot is sure to be a welcome feature for people who shoot photos or videos with cameras that use SD cards. The slot recognizes the card as a standard USB device. The feature worked well on the laptop I tested. The card showed up promptly and behaved as a memory card should. I tried loading OS X on to and then booting the machine with the SD card, which worked just fine, too; this capability is a genuine consumer-friendly convenience.

Apple says that the MacBook Pros support the following cards: SD (which holds (4MB to 4GB of data), SDHC (which holds 4GB to 32GB of data), microSD (with and adapter), and miniSD (with an adapter). It does not support SDXC, a brand new card specification that theoretically can support up to 2TB of storage, but this card is not yet available on the open market.

Users who have invested in Express Card hardware will lament the decision to eliminate the ExpressCard/34 slot, especially photographers and videographers who use the slot for a CompactFlash adapter because their cameras do not support SD cards, or folks who use eSATA or 3G Express Cards. Apple estimates that customers who actually use the Express Card slot make up a single-digit percentage of its laptop customer base. The 17-inch model retains its ExpressCard/34 slot, making it the only option for anyone who really needs it.

The space recovered from a removable battery is now taken up by a larger, flatter, more compact, and longer-lasting battery. The svelte new lithium-polymer batteries differ from the traditional lithium-ion cells of the past. A new characteristic of the battery, called Adaptive Charging, is designed to optimize each charge in order to prolong the battery's lifespan. The new battery contains a chip that monitors things like charge level and temperature and communicates this information to the computer. An advanced algorithm processes this information to determine the optimal charging current.

Because of this, Apple says that instead of the typical 300 recharges that most notebook batteries get, the new MacBook Pro batteries can survive 1,000 charges, or approximately five years, before reaching 80 percent of original capacity. Only time will tell if that claim meets the test of reality. It's hard to objectively judge whether non-removable batteries is inherently a pro or a con: Some people will be totally happy never to handle the battery. Others will feel positively deprived without the ability to swap batteries (on a long flight, for example).

Better screen graphics. The glossy screen of the previous generation of MacBook Pros literally popped with vivid color and smoldered with distinctive grayscale tones. Its blacks were deep and rich. Now, Apple says that the display is even better, offering 60 percent greater color gamut than earlier MacBook Pro generations. Color gamut is not a measure of brightness, sharpness, or resolution. Rather, it represents the range of colors that a device can display. MacBook Pro displays are accompanied by LED (light-emitting diode) backlight technology that promotes better representation of a wider range of colors onscreen. And, while no one really expected it, there is still no matte screen option for this notebook display, and likely never will be. People who care about this (and there are many who feel strongly) will continue to be disappointed.

Greener than ever. The new line of MacBook Pros (including the 15-inch models) continue the environmental initiatives of the recent past to include arsenic-free display glass, BFR free construction, mercury-free LED-backlit display, PVC (polyvinyl chloride)-free internal cables, recyclable aluminum and glass, reduced packaging, and an EPEAT (Electronic Product Environmental Assessment Tool) Gold rating. And Apple's notebooks now meet the EPA's newest Energy Star Version 5.0 requirements.
New 15-inch MacBook Pros: Speedmark performance.

The new line of 15-inch MacBook Pros features three models instead of two. Like the new 13-inch pro models and the white 2.13GHz MacBook ( Macworld rated 4.5 out of 5 mice ), the bottom-of-the-line 15-inch 2.53GHz MacBook Pro features only the NVIDIA GeForce 9400M integrated graphics chip. The other two new 15-inch pro models have both the 9400M and a discrete NVIDIA GeForce 9600M GT graphics chip. The new pro models also contain the more powerful DDR3 SDRAM, as compared with the MacBook's DDR2 memory. The new 15-inch pro models also have 4GB of 1066MHz DDR3 SDRAM, upgradeable to 8GB.

The new MacBook Pros are clearly in their own class, as reflected in their Speedmark scores. While our benchmarks show that, overall, the three new systems are fairly close in terms of overall performance--the high-end 2.8GHz model outpaced the low-end 2.53 model by 9.7 percent--a more compelling performance narrative based on the dual graphics chips is told with our Quake 4 frame rate test. In Quake, the high-end model was more than twice as fast as the low-end model and outpaced the mid-model 2.66GHz by more than 10 percent. We observed similar disparities with the Call of Duty 4 test: again the high-end model squeezed more than twice as many frames per second as the low-end model but was on par with the mid-model. If you're a gamer, you'll benefit from the dual graphics setup. Plus, the high-end 15-incher has twice the video RAM of the mid-model.

Value
Compared to the previous MacBook Pro generation, prices for all of these models have dropped substantially, at first blush. If you take a closer look on a model-by-model basis compared to previous MacBook Pro models, you'll find some compromises were made. But the end results are slightly lower prices overall.

Take, for example, the new 2.53GHz pro model. It’s cheaper than the older 2.53GHz model (Macworld rated 4 out of 5 mice) but the new 2.53GHz pro model lacks the 9600M GT graphics chip that the older model had. Another example: the new 2.66GHz pro model with the dual graphics setup is 0 less than the older 2.66GHz MacBook Pro ( Macworld rated 4 out of 5 mice ), but the new model has half the amount of video memory as the older model. The new top-of-the-line 2.8GHz model with a 500GB hard drive.

In addition to its upgraded RAM configurations, the new 2.53GHz and the 2.66GHz models come with 3MB of shared L2 cache. The 2.8GHz model ships with 6MB of shared L2 cache. All models retain the 1,066MHz frontside bus and built-in AirPort Extreme Wi-Fi with 3Mbps Bluetooth 2.1 + EDR. The 15-inchers come standard with Serial ATA 5,400 rpm hard drives of 250GB, 320GB, or 500GB respectively. Both of the higher end 15-inch models have the dual graphics setup with the NVIDIA GeForce 9400M and GeForce 9600M GT, but the amount of video RAM for the 9600M GT differs-the 2.66GHz MacBook has 256MB, while the 2.8GHz has 512MB. Another part of the increased value of these notebooks is their expandability. The new 15-inchers have more upgrade capacity than they did before and additional build-to-order options, including: a 3.06GHz processor; a maximum of 8GB of RAM; a 500GB 7,200 rpm hard drive; and a 256GB solid state drive.If you want a smaller, lighter notebook to tote around, you may be glad to note that the 13-inch 2.53GHz MacBook Pro's benchmarks results were nearly identical to the 15-inch 2.53GHz model.

Battery life
How long can you sit on a plane and work (or play) on your machine? Apple says the batteries on the 15-inch MacBook Pro will last 7 hours without having to be recharged, basically a day's work, if you're using only the NVIDIA GeForce 9400M integrated graphics processor. Cut about an hour off of that total if you're using higher powered graphics of the NVIDIA 9600M GT graphics processor.

MacWorld’s buying advice
The 15-inch MacBook Pro 2.53GHz, 2.66GHz, and 2.8GHz sport faster processors on the high end, higher RAM capacity, a larger solid-state drive option, longer-life battery, an improved display, and an SD memory-card slot (in lieu of the ExpressCard/34 slot found on the previous version). All of these changes are accompanied by lower prices.

If you already have a anybody MacBook Pro, you will already have most of the great features these new models have to offer. However, if you're a switcher, a new buyer, or have one of Apple's older notebook models, you have a cornucopia of excellent choices at more advantageous prices than before. Gamers will want to consider only the mid- or high-end 15-inch model.