The OS by itself is very solid .. but introduce any 3rd party app into the picture and things become extremely flaky. But this is true of nearly every Palm environment I've been in. While I do realize that this could be an issue with the software mfger than the platform, Palm is still one of the easier mobility platforms to write to... and yet experiences more crashes than any other port of the program. I also dont like the fact that a lot of these crashes take down the system. If you can believe it, I've had palm devices (v.4.xx) that required more resets than my Win 98
From my experience, accessories are always more dicey to recognize on a palm device than with any other PDA I've ever owned. Honestly, every palm I've worked with, has been adequate at a number of tasks but never good at it... most, required too much coaxing and cajoling. I havent had that experience with the alternatives.
I just find it funny that after years of trying to take over a blossoming market of combining a PDA+Phone with the "merger" with Handspring, I find it funny that the Treo wants to feature a Microsoft or a Blackberry OS