I'm fairly impressed with my Dell Axim x51v. Although they are called "slow" (apparently because of the combination of WM5 and VGA graphics), I can't say that it's a problem on mine.
What DOES disappoint me, however, is the inability of WM5 to sync with my Exchange Server's "Public Folders". That's where I keep my shared Company contacts. I'm going to have to copy all those contacts to a "Persona"l Contact folder in order to sync them with my Dell Axim.
Regarding Palm vs. WM5, I've only used older Palms, but I wouldn't claim that WV5 is THAT similar to "full" Windows operating systems. It's pretty different. I am pretty impressed with WM5's handwriting recognition, thought. It works amazingly well for data entry. MUCH better than I expected. I assume that Palm does something similar now.