From what I've heard, Windows PDA's need more processing power, and more storage the it's equivalent Palm device.
Haven't ever owned a Windows PDA, but I've very happy with the T|X I purchased about a month ago.
My suggestion... purchase a T|X from a store with a generous return policy, try it out for a week or two, and decide. If you really hate it, you can return it.
I doubt it'll be going back to the store, however.
(By the way, the Palm Store near me allows 15 days to return your Palm device, if you're dissatisfied)
Good luck!