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