Who says it can't be done? Nobody actually but that's beside the point.. I've been running an XDA Orbit for the last couple of weeks alongside my (less than trusty) treo 680. The treo takes care of my email stuff via Snappermail, texting and my scheduling whilst the XDA is used for browsing, phone calls (the treo has decided that phone calls are not part of its' job spec for some reason) and various bits'n'bobs such as word and excel documents editing and viewing. The XDA also has a built in FM Radio...this is one of those things I've never had on a pda before and I've found it to be a real boon.
Is palm better than WM? Who can say for sure? There are things I prefer about the palm o/s and there are things I like more on WM5..if I could combine aspects of the two I'd have the perfect pda/smartphone.
The palm o/s is generally quicker around the menus and at opening apps whereas WM, through Opera Mobile, offers a superior internet browsing experience and more reliable syncing. Palm apps also tend to be more intuitive to use compared to their WM counterparts.
I have to say the XDA is one of the nicest devices I have ever owned...it looks and feels good and has that wonderful slim form-factor but still with very good battery performance. The lack of a built in keyboard, for nme, is not a factor as the onboard options and 3rd party software available reduce this to a trifling inconvenience. I'd never thought I'd say this and shhhhhhhh...whisper it very very quietly...Windows Mobile is more stable than palm...yep siree, only one reset in 2 weeks on the XDA and in comparison, numerous apparantly random resets on the treo. Looks like WM is really getting its act together of late.
At the moment, I like them both equally and I 'd hate to have to choose between the two as they both have many things on their side over each other. The Dark side is perhaps not as dark as it was a year or so ago.