We have a few of these cute little Atom-based netbooks at work. Some of the senior staff have tried them on business trips. The verdict: these little boxes are painfully slow, even if all you do is websurf and grab email. If you need speed, you need a real laptop, IMHO. I would weigh very carefully the cost of any netbook upgrades against the rather modest gains there are to be had in performance. YMMV
My verdict is neither lightning fast nor painfully slow. I have transferred 10 DVD movies to mine in just over 20 minutes. The portability and battery life are awesome. It runs Skype or my Magic Jack fine for travel in other countries. I will be taking my 14" HP when I go to Houston all next month but the Mini is great for short trips.