I don't know about pocket pc. but Palm works pretty well, it comes with something called documents to go, which allows you to open, edit, and create microsoft word, powerpoint, and excel files. I think they have this for pocket pc as well.
Oh, btw, pocket pc isn't officially supported for mac by the manufacturers. To sync you'll have to buy this little diddy called The Missing Sync. Which can be seen in the link below
http://www.markspace.com/products.html
As with advantages, I believe pocket pc is better at multi-tasking that palm os is, palm is a one-application-open-at-a-time sort of OS; I find it very very stable because of this but some just can't live with that sort of usage. My family has always been a palm family ever since my dad tried using Windows CE 3.1, could never get the thing to sync with our computer. It's still collecting dust in a shelf behind me (8 years old now). I use a Tungsten E2 and find it suits me well, a charge lasts me 4 weeks if I use it only for scheduling. I use it as an MP3 player sometimes when I don't feel like lugging an ipod in my already full pockets and play some videos I compressed for it when I'm bored (though the psp does the job better because of it's bigger screen).
I got my Palm Tungsten E2 for 150 dollars. For some reason my Office Max had them for $199 (usually 250) and also had a $50 dollar rebate on it. I think that was a good price
Hotsync for palm also works with isync if you enable it, allowing you to use iCal/address book instead of palm desktop. Which is a nice little feature. But the missing sync would allow you to do so as well for pocket pc.
Hope that helped a bit.
Good Luck!