Another eeeXubuntu user here
I have to say that the standard Linux install that the eeePC works just fine once you install the "advanced" desktop. For office apps, email & browsing you don't need more. eeeXubuntu is slower to load, and needs more disc space, but has a shedload more applications. I've found that on business trips I tend to take the eeePC now and leave the "sensible" laptop at home, so it was worth upgrading the OS and the memory (I put 2 gig in). In fact I went further and installed the Gnome desktop, which I prefer to the XFCE one that is standard with XUbuntu.
Also, I run Ubuntu on all my other PCs, so there was a benefit of compatibility and familiarity