A really good device overall (high resolution, great sound, processing tips), but the disadvantages should not be ignored:
1. The display is very fine, but not particularly bright. My old 13er MacBook Air appeared brighter. In addition, some applications are not yet adapted (not the problem the laptop - but you should know, Office 2011, for example, very, very pixelated)
2. No Kensington Lock
3. No external battery indicator like old MacBook Pros (I always found very handy)
4. In places bitchy HDMI output (seems problems under 10.7 to give and with HDMI switching between internal and dedicated graphics card). I had problems with wireless HDMI transmitter (for projector mounted on the ceiling) and an Asus monitor, with the other laptops so far had no problems
5. No IRDA port (yes, I miss actually - I like the Apple Remote uses, even if comparable with iPhone / Android can achieve)
6. Battery term of between 4 and 5 hours (WLAN on, screen brightness at 100%) - Me So just barely good
7. OSX 10.7 is me in the first 4 weeks good half a dozen times crashed (I did not have in the 5 years before in total), but no data is lost, to be better with 10.8 + Retina
8. Laptop works (esp. GUI) is not as fast as it should be in the data sheet actually
9. Secure any known: you can not fix quasi, therefore AppleCare duty
10. At least under 10.7: insufficiently stable wireless (WLAN breaks every now and then together)
11. New MagSafe adapter found, the old better (the cable led nicely to the back)
Would I buy the device again? Of course. But at that price one should emphasize the negative points, I think.