I had the 512MB, 8GB SSD, Linux version for 2 days and absolutely love it. When considering mini-notebooks, my only concern was the size of the keyboard. The Aspire One's keyboard is comfortable to type, but it took me about 30 minutes to get used to it. After that my typing speed was up again. The screen is bright, sharp, and easy to read. My only complain is the fan noise. The high pitch whining does get annoying. However, with music on at a low/comfortable volume, it is hardly noticeable.
I got the Aspire One at Circuit City on Sunday, but the fan was just too loud so I exchanged it today. It seems to be softer but not silent like I hoped. Looks like this problem is widespread (there's a thread, "Fan problem" dedicated to it). Hope it will be solved by future firmware upgrades.