MacBook – Which model of Macintosh has the longest battery life

Actually, an Apple battery gives you the percentage of its original capacity that it currently has. You can access that number through the free CoconutBattery app.

If you want to do your own benchmark, I recommend using BOINC and supporting a grid computing project, like SETI@home. These basically use 100% of your CPU from the moment you turn the program on until the moment you turn it off. This drains the battery pretty quick. Just be careful to check temperatures to make sure the computer doesn't overheat, especially with a MacBook Air. You probably should quit extra apps, but it shouldn't matter too much.

I'm going to suggest that for development - as opposed to for gaming - you may want to consider setting up a Windows virtual machine using VMWare Fusion or Parallels Desktop. Both of these will apparently let you run them from a Bootcamp Windows partition so that you can boot into Windows for gaming but use a VM for other tasks, all using the same Windows installation. I have no personal experience with that, as I use a VM exclusively, mostly for Visual Studio as well.

The reason is that this will give you Visual Studio on your Mac desktop so that you can run Mac apps for everything else.

FAIR WARNING! If you start using a Mac, you will find Windows increasingly limiting and badly designed compared to OS X. I'm serious; I much prefer working in MacOS now, even though I spend most of my day in Win7.