I also use my MacBook Air as my main computer. The only thing I don't use it for is to play disks. When I have to do that I just use the shared disk drive in our desktop PC that's in our house. (Though I don't really need to use disks that often)
Just wish I had more storage in my MBA I mean I can survive with 64 gigs, but it's kinda annoying having to put large files and folders on my external and having to plug that in when I want to access them.
You can upgrade the SSD in the 2011 MBAs. OWC has them in stock.