I think you illustrate one of the main problems when compare the MacBook Air running Windows 7 and the Thinkpad. Windows 7 is well optimized for the Thinkpad by Lenovo and therefore the hardware performs at peak levels. The MacBook Air with OS X is well optimized by Apple to maximize performance of the Air. So even though hardware may be evenly matched, when you just load Windows 7 on the Air it requires some end user tweaks.
True enough. I was very close to returning the Air until someone suggested installing the fan control program. I appreciate that the Air is optimized for running OSX, but I do need to run Windows. I could go with a Sony or Lenovo laptop, but nothing beats the Air in terms of portability + performance.
If you are just looking at hardware as described above and end user applications, wouldn't the MacBook Air win the decision hands down? Able to run windows 7 thus PC apps. In addition, the Air runs OS X and all Mac Apps. Now the Lenovo, only able to run Windows OS therefore limited to PC apps, unable to access OS X apps. The Air is 34% lower in weight in the 11.6 form factor.
Looking at it from that angle the MacBook Air would win.
And again, so true! One of the reasons I started looking at Macs is because of iOS integration. I kept hearing about various Mac applications, including iLife, that would make working with my iOS devices easier/more convenient. So far, none of them has been compelling enough to make me switch to OSX -- I'm too used to Windows conventions when it comes to getting work done, and don't see a point in putting myself through the hassle of learning to do things the Mac way. But it's nice to know I have the option of booting into OSX if a "must-have" Mac-only app comes along. And I'm looking forward to Lion, with its addition of iOS-like features. But for now, running Windows on Macs is, for me, the best of both worlds.