There was a time I'm sure it would have bothered me whether it was my main machine or not, but a few years ago my iMac's internal 1TB drive went kaput, and rather than put any money into the machine, I opted for a 64GB SSD, and decided to really start using my external storage much more efficiently. When I bought my MBA with 128GB I already knew it would be no problem because my main home machine is only 64GB, and I don't regret it one bit. I've got a NAS, plus I use Dropbox, SugarSync and SpiderOak (all free), plus I've got 2 more external drives (one attached to the NAS another to my AirportExtreme) and I have plenty of storage and never ever wish I had more - not sure what I'd do at this point with more storage, it'd simply sit there idle.