I purchased the newly updated 13" MacBook Pro and the newly updated 13" MacBook Air the day they were announced at WWDC and released for sale in June 2012. (My 13" MacBook Pro is the 2.9 GHz i7 model, and my MacBook Air is factory upgraded to a 2.0 GHz i7 processor and 8GB RAM.)
After using the two machines side-by-side for a couple weeks now, I can say that the MacBook Air outperforms the MacBook Pro in almost every task and in terms of overall speed and performance. Compared with the newly refreshed and updated Air, the new MacBook Pro is frankly a significant disappointment, and I've pretty much stopped using it altogether in favor of the faster Air. Despite the Air's slower CPU clock speed, it performs faster than the Pro in actual tasks due to the performance boost afforded by it's SSD hard drive. The SSD drive on the MacBook Air makes an enormous difference in everything from casual web browsing to video editing.
If you're debating which 13" MacBook to buy, the 13" MacBook Air or the 13" MacBook Pro, here's a side-by-side comparison...
Speed and Performance: Advantage MacBook Air
Apart from the hard drives and port configurations, the technology inside the machines is virtually identical in both the newly refreshed MacBook Air and MacBook Pro. Both Pros and Airs come with either i5 or i7 Intel "Ivy Bridge" processors, Intel HD Graphics 4000, USB 3.0, and lightning-fast Thunderbolt ports. While the MacBook Air models are at a disadvantage to the MacBook Pro models in terms of CPU clock speeds, any performance disadvantage from the processor speed is more than made up for by the lightning fast performance of the Air's SSD hard drive, which Apple markets as "Flash" storage. In everyday tasks from gaming to web browsing to watching Flash movies and editing video, the MacBook Air is faster significantly faster in virtually every task. The Air boots up in less than 12 seconds while the Pro takes upwards of one minute.
Screen: Advantage MacBook Air
If you've never used a MacBook Air, much less the new Retina display 15" MacBook Pro, then you won't notice just how outdated the MacBook pro's screen is. However, once you get used to the super high resolution 1440 x 900 LED display on the MacBook Air, the 1280 x 800 back-lit LED display on the MacBook Pro looks downright grainy and primitive. Simply put, once you get used to a higher resolution display, the 1280 x 800 display on the 13" MacBook Pro just isn't acceptable. Even for simple tasks like email or word processing where you wouldn't think the resolution would matter, the graphics look grainy and pixelated, which just isn't acceptable for a pro-level laptop in 2012.
Upgradability: Advantage MacBook Pro
The Pro's only major advantage over the Air comes in terms of the flexibility of its hardware, ease of repair, and upgradability. With only a screw driver and about 10 minutes of your time, you can add more memory to the Pro, replace the hard drive, and even add a second hard drive in place of the optical disc drive. The Air, on the other hand, is stuck in the configuration you purchase it in except that you can opt to replace the SSD "Flash" hard drive with a higher capacity SSD drive.
Design, Weight, Portability, Battery Life, and Form Factor: Advantage MacBook Air
The MacBook Air is the most beautiful computer ever produced by man, and the MacBook Pro looks like it's older, pudgy relative. The Air's aluminum case is impeccably designed, almost tailored to accommodate the necessary internal components, while maintaining practical ergonomics. It's an incredibly thin, svelte, sexy little notebook. The MacBook Air's aluminum case seems sturdy and durable, and its mechanics are very similar to the time-test unibody construction of the MacBook Pro. The MacBook Pro, on the other hand, is a bit of a dinosaur in its bulky circa 2006 unibody. The Pro is heavier than a half gallon of milk at 4.5 lbs, while the MacBook Air weighs in at less than 2.9 lbs. Battery life is roughly even on both machines at anywhere from 4 to 7 hours depending on workload and settings.
Summary Judgement: Buy the MacBook Air (or opt for the new 15" Retina display MacBook Pro)
Simply put, the guts of the MacBook Air and the MacBook Pro are basically the same, but the Air's SSD hard drive gives it a tremendously significant boost in performance. Sadly, the MacBook Pro's 5400-rpm hard drive leaves the machine unable to capitalize on the newest, most expensive Intel "Ivy Bridge" i5 and i7 processors that you're paying a $300 premium for in the newly updated Pros. If you are going to buy a Pro, invest the extra money and get it upgraded with a SSD hard drive and get an extra external hard drive if you need additional cheap storage space for multimedia files. When you also consider the superior display, lighter weight, increased portability, and lower price of the MacBook Air, it's hard to find a reason to justify purchasing the current 13" MacBook Pro, which to me looks like a dinosaur rapidly headed for extinction.
Specs on the models compared:
13" MacBook Air (mid 2012) factory upgraded to the 2.0 GHz dual core i7 processor and factory upgraded to 8 GB RAM (1600MHz DDR3L SDRAM) with standard 256 GB SSD ("Flash") hard drive
13" MacBook Pro (mid 2012) with 2.9 GHz dual core i7 processor, 8 GB RAM (1600MHz DDR3L SDRAM), and 750GB Serial ATA Drive @ 5400 rpm
Both feature Intel HD 4000 Graphics, 3.0 USB, Thunderbolt, 802.11n, etc.