I don't have any problem with it, even on a single processor G4 system. The Genesi system might be slightly slower, but I've been using since I had a 733 Mhz processor in my Powermac and the only thing that was slow were certain graphics packages (no decent support for Flash under PPC Linux either - rather like MorphOS).
Flash and Linux is a bad combo anyway.
Thing is, when you're running with netbooks with low-power CPU's such as the Intel Nano, you dont have that kind of raw power that you have with a 733 MHz PPC! Thus, a full-fledged distribution
will feel sluggish. It's not as much a problem with Ubuntu, as it is a problem with most distros using Gnome/KDE as stanard DE's. A custom install using Openbox or another light-weight distro will be much snappier.
