Just last week I migrated from a rev. A (1.6/80GB HDD) to a rev. C (2.13/128GB SSD) and it's the best move I made. I didn't have my A long (bought it new but only had it 10 months) but reading here I decided the SSD route was the way to go.
I've had my C a week and just love it!
I had a few netbooks when the netbook craze started. I eventually became bored with them and when compared to the MBA, the MBA wins hands down!! Obviously the MBA has a different audience than a netbook based on pricing, but if one can swing it, they definitely should consider it.
I never knew what all the fuss over the SSD was about when I first read it here. Now that I've had the chance to play and see, there is an absolute difference. I don't think so much a weight factor (as specs for both say 3#'s) but there is a bump up performance-wise with SSD.
If you can swing it, do it. You won't be sad if you do!