Thanks you. I think it's just the thought of having a clean installed system and get the montain lion thumbstick with the air is better than having the lion version then upgrade if there's a reinstall needed (if that ever will happen true).
But I'll guess I pull the trigger in the weekend. I'll get the 11 version since I want portability but sadly I will do lots of music and sheet music writing so I'll be mostly working on a second screen when not on the go (which is yet another investment. But I think I will just simply have to test this setup out).
Thanks
Fred