An entry-level Acer laptop cannot be expected to be blindingly fast, but with the specs of this machine, things should run smoothly at least. That didn't happen with Vista tho: startup and shutdown times were in the vicinity of geological; sometimes the system just hung up for half a minute or so with no apparent reason while the disk was spinning furiously. Changing something so trivial as network settings took a long digging through windows and menus structured and named according to some unknown and perverted logic.
Moreover, requests to confirm actions popped up every few minutes, and the final insult was that Skype would not work: it could keep trying to connect for hours without doing anything, and the application was most often not responding. In my situation Skype is very important to keep in touch with my family and other people in Italy.
So I decided to relegate Vista to the backup partition and install Ubuntu 10.04 in its place. Well, it has been a few days but my computing experience has improved greatly: the computer is finally springy, it starts up and shuts down in reasonable times and all the applications I need work fast and well. There are no problems with hardware, either. And I can be root, the terror of the filesystem!
I have no regrets and welcome Ubuntu.