How much disk space is already used by the OS and included apps on a new MacBook Air I'm considering getting a new MacBook Air, and wondering whether to get the extra diskspace that the 256GB model offers. 

128GB seems like it might be plenty but then I remembered that the OS takes up some space the pre installed apps also take up some space. So an upgrade from 128 to 256 would actually more than double the usable capacity of the machine. But by how much?

So my question is on a brand new, straight out of the box, July 2011 MacBook Air 13" if you right click on the mac disk and Get Info how much available space does it report.
I have a 128GB Air with Lion and iLife '11 ... which is what, by default, would come on a new Air from the Apple Store or authorized reseller. I have other apps, so this is only a guess, but...


Lion: 4-5 GB 
iLife '11: 5 GB 
Recovery Partition: 650 MB


So, on a 128GB Air, you should see about 115-118GB free space. On a 256GB Air, you would see about 243-246GB free space.