I just picked up the just released 2011 11" MacBook Air in the hopes of using that to replace my 2011 15" MacBook Pro. In the event it didn't perform well enough it would be given to the wife (actually, this was the original plan anyways, so if it can be a decent development machine, all the better)...
Here are the specs (Both with Lion and Xcode 4.2 and iOS 5 Beta 4):
Decked out 2011 11" MacBook Air
- 1.8Ghz Core i7
- 256GB SSD (The faster Samsung one)
- 4GB Memory
Decked out 2011 15" MacBook Pro
- 2.3GHz Core i7
- 400GB SSD (OWC w/SandForce, not OEM)
- 8GB Memory
For me the only thing that matters is Xcode performance. I just did a project with the following characteristics, and measured a build from the time of pushing play to the time of the simulator launching with the login on the build displayed.
- 224 Source Files
- 63 XIB's
- 419 Resources
- Clean Build
MacBook Air: 38 seconds
MacBook Pro: 16 seconds
- Repeat Build (No Clean, Simulator Left Running)
MacBook Air: 8 seconds
MacBook Pro: 8 seconds
It was expected the MacBook Pro would be faster. From a clean build it's significantly faster. From an existing build where you're touching a few files Xcode indexing to know what's changed or not makes it a wash. As we're mostly just changing a couple files at a time, the MacBook Air seems fast enough for development. Just know that the clean build will take almost twice as long.
Also, the actual copying of resources, launching the simulator, etc. between the two took about the same time. There was a moderate difference in the compilation times, but the static analysis is where the MacBook Air lost out. The MacBook Pro killed it with the extra two cores and processor speed.
Now, the debate... I think I'm going to try out the MacBook Air and see how it goes...
UPDATE: After using the MacBook Air I decided to stick with the MacBook Pro. That extra speed really matters when a client is looking over your shoulder. Although, if you are used to a non-SSD MacBook Pro (particularly, the 2010 variety) you'll be happy with the performance of the Air.