I recently bought a 128 GB 13¨ Air to replace my 2010 one, which had the same size SSD. When I got it I used the backup I had from the old Air and restored it on the new one, so they should be identical right? Nope, while there was about 55 GB free on the old one, the new one has about 12 gb less free space. The 2013 model has 8 gb RAM while the old one has 4 so there should only be a 4 gb difference? I've compared map-sizes and can not for the life of me understand where the other 8 or so Gb have ended up. Is there some new stuff on the 2013 models that take up a lot of space even though they run the same OS version and are using the same backup?