The most important single thing that can be said about PDAs is that they aren't like PCs.
With a PC, you expect to load any software on it and usually it does work.
With a PDA, it is very much a matter of luck. Perhaps 30% works perfectly, another 30% works but needs a reset before it runs, and the rest doesn't work.
And nobody will sort it out, because all the mfgs have comprehensively washed their hands of support. Even HP.
The one thing that seems to work well are the basic caendar etc functions but.... for those you don't need a pocket/pc device, a palm/os one will do, will cost a lot less and runs for a lot longer.
PDAs are really single-application devices, originally designed for the executive market where the sysadmin tests and deploys the specific apps that the company needs, and no more. Anything else that appears to work is a bonus.
Probably the biggest joke (in reliability terms) I've ever seen on a PDA was various GPS moving-map applications.