I am a fourth year and I use a pocket pc. I had a palm for 2 years and now have a pocket pc. I had problems with my palm and have had a much better experience with my pocket pc. Which you should get depends on what you intend on using it for.
Here is my opinion:
-If you are only interested in using the handheld device for datebook/notes/medical reference, then a palm is fine. Just make sure that you get one of the models that has an expansion slot (for an SD card) because many of the books are very large. On palm.com the cheapest current palm model with an expansion card is the tungsten E for $199.
-Most medical software is now available for both palm os and pocket pc, so that should not be a big part of your decision. One difference is that epocrates is not free for pocket pc. Also, some of the software for pocket pc's include more images/tables than the same software for palm os.
-If you are interested in using your handheld for other things (like internet, music, documents), I would go with a pocket pc. I love my pocket pc because i can look up something in 5mcc or harrisons and then log onto the internet for more info if I need to (a lot of schools and hospitals have wireless internet now). Also, the pocket pc's have faster processors and move through info faster. It used to take my palm 30 seconds to open tabers medical dictionary. A pocket pc will probably cost 300-400 depending on what features you want.