So - I bit the bullet and upgraded from a Rev A 1.6GHz 80GB HDD MBA - to a Rev B 1.86GHz 128GB SSD MBA. I wanted to post my observations on what it's like to upgrade - I know many Rev A owners have - or are thinking about - upgrading to Rev B. In this post/comparison, I refer to "Rev A" and "Rev B". The Rev A is my older 1.6GHz 80GB HDD MBA. The Rev B is my new 1.86GHz 128GB SSD MBA Caveat - Unlike some (but not all!) Rev A MBA owners, I love my Rev A MBA. I've had zero problems with it. It runs cool and I have not experienced any core shut downs. It would heat up when most laptops normally heat up and the fans would kick. It would cool down quickly when I moved on to something else. With video it never stuttered... Perhaps my Rev A has run so nicely because I don't ask a lot of it. It is a second Mac to my mac pro - I use it primarily for email, word processing, iTunes movies and web surfing - on the couch and on the road. It has REALLY been a great laptop and I have nothing bad to say about it. So why did I update? I wanted more space. I have my Rev A setup to duel boot (Vista) for business uses from time to time when I travel. That kills a chunk of space. Also - with the Rev A, I compromised - by not having my music, photos and other large files with me. Not a bad tradeoff. But the Rev B's larger hard drive was enticing - additionally, the Rev A has been so great, I'm willing to make the investment to have the latest/greatest version of the Air because it is such a leap/improvement over the Rev A - both speed and graphics-wise. I won't spend time on the A's form factor - those of you that own one already get that - it's great... So here are my observations - they are based on the things I can see and observe - not Xbench scores - real world use - and hopefully it will give you an idea of the differences between Rev A and Rev B. As I type this, I have my Rev A right next to me - side by side with the Rev B. My observations: 1) Packaging - The Rev B's packaging was similar to the Rev A's in terms of layout, but the Rev A packaging materials were FAR nicer. The Rev B's packaging is more in-line with the other Apple notebooks - white briefcase with handle. I really liked the packaging of the Rev A - very solid and heavy duty in comparison - it set the original Air apart. 2) Sounds - The first thing I noticed when starting it up: The Rev B (SSD drive) is dead quiet. The Rev A's subtle hum and hard drive noises are (obviously) completely gone. The click and general noises of the Rev A's hard drive was never something I really noticed - until it was gone... The Rev B is eerily quiet! Upgraders from the Rev A HDD will notice the difference. 3) Trackpad button - The Rev A's track pad button is comparatively mushy - it takes more travel to make a click. The Rev B's is very tight - less play. The Rev A's button never bothered me - interesting that the Rev B's is tighter - a purposeful improvement? 4) Keyboard - This was a surprise - and I had to double check this. The Rev B keyboard has been improved in a similar way to the trackpad button - the keys are quieter and seem to be more tightly secured. It's hard to explain, but the improvement has resulted in a typing experience that is quieter - less "rattley". To see what I mean, run your fingers back/forth lightly over a Rev A keyboard and the keys have more play and make more noise due to the looser keys. The Rev B is tighter when you do this - less play and less noise. 5) Screen - Many complain that the Rev B's screen has faint lines. I've seen them on the store models, and they do exist. It was a concerned when buying my Rev B, but I have yet to read about someone who was denied a refund by Apple if they had lines on the MBA screen. Bottom line - Apple stands behind their products - I was not afraid to risk having to make a return. I've looked really hard at my Rev B and, if I get my head in just the right place and the screen tilted just right, I can see some lines - but they're REALLY hard to find and they are not as bad as what I've seen in the Apple store display Rev B airs. Looking at my Rev A, doing the same contortions, I can actually make out similar - albeit even fainter lines. My Rev B is a keeper - I really can't see the lines during normal use. Side by side, the Rev A and Rev B screens look identical to me. Same brightness, color saturation, etc, etc. I have both setup using the same display profile - the default "Color LCD" profile. I've played the same movie and frozen clips on the same frame - the screens look absolutely identical. 6) Display output - the Rev B has the newer Mini DisplayPort display - which replaces the Rev A's Mini DVI port. Unlike the Rev A, the Rev B does not include the VGA and DVI adapters. They're yours to purchase separately for an extra $29 each. Typical of Apple to remove extras in the Rev B edition... I never used the Rev A adapters and chose not to buy them for the Rev B until I need them. 7) 4 Finger gestures - I REALLY like these. I was surprised at how well they work and how much I use them. Four fingers up - see the desktop. Four down - Expose (awesome). Four to the right or left - switch applications. Good stuff. I like it. 8) Graphics - The Nvidia Graphics chip is a huge leap over the earlier Intel chip. I've run several games on my Rev B that could not run on the Rev A Air and they are actually very playable! I like this - I play games from time to time when I travel - while I fly... This is a great improvement and I like the ability to use applications that require mid-level graphics abilities. 9) Performance - I saved the best for last. This is the area where I'm really pleasantly surprised. The Rev B's performance is NOTICEABLY faster. Surprisingly so. In some respects it is faster than my Mac Pro (But not at the heavy lifting - not by a long shot!) Here are some observations (note that applications start times are after a restart of OSX - I know that applications can be cached and load much more quickly the second time around). Some of these differences may seem small, but they are huge - look at your watch and tick off 14 seconds... That's what it takes in additional time for Word to load on my Rev A. You start to really appreciate the SSD drive... - Start from complete shut down - Rev A: 56 Seconds; Rev B: 28 Seconds - Restart - Rev A: 58 Seconds; Rev B: 31 Seconds - Shut Down - Rev A: 3 Seconds; Rev B: 2 Seconds - Start Safari and load page (boston.com) - Rev A: 18 Seconds; Rev B: 7 Seconds - Start Entourage - Rev A: 24 Seconds; Rev B: 8 Seconds - Start iTunes - Rev A: 9 Seconds; Rev B: 4 Seconds - Open MS Word - Rev A: 17 Seconds; Rev B: 3 Seconds If you're thinking about upgrading - it's a nice improvement. While I have the Rev A and Rev B in hand, let me know if there is anything else you want me to compare. If it's not too involved, I'll do it.