I use a Pocket PC, specifically, a Dell Axim X5 (I bought it almost 3 years ago), and it has been awesome ever since. I develop software that runs on the Windows platform so I thought it only natural to have a PDA that has an OS that I am familiar with.
My Axim is pretty supped up. I have a 512MB Compact Flash Card, 5 256MB SD Cards (lots of my music on these), a Belkin Compact Flash Wireless Card and tons of software.
I use AgendaFusion as my PIM. It syncs perfectly with Outlook. I have everything in my hand that I would have on my desk. I can read Word .doc files, Excel .xls files, Power Point files, .pdf files, just about anything.
I started storing documents on my 512MB card in folders like @Client-Proposals, @Research and so on. I use TotalCommander as a File Explorer which has a search feature. However it doesn't search in a document. I either need to find an app that does this or write one myself
All in all I love the Pocket PC platform. I am used to the interface, the software, and if I truly need something I can't buy I will write it.
Wishes? Interface to OneNote (which I am using heavily now), GTD add-in for Outlook (maybe I need to write one for AgendaFusion), and as I mentioned a search utility that will let me search in files not just file names or types. Other than that I'm really cookin! Hope that helps.