Palm OS sync is still being supported for Macs.
Pocket PC requires a third-party sync option (Missing Sync), but several people on this thread have used it with good experience.
A big part of the decision is what you are using it for.
For example, if Wi-Fi is a must, then the Palm OS options are limited. You could only use the LifeDrive, Tungsten C or one of their other Palms with the additional Wi-Fi card.
This is one area that people have felt that Palm is a bit lagging.
If your primarily goal is information management, Palm OS is very user-friendly.
I myself use have used Palm OS for several years & find it to be excellent for my needs.
I do believe that most Palms will work fine for Mac, but on the Palm website (
link here), they recommend either the Zire 31 or Zire 72.
Hope that helps - good luck!