I bought one
I bought an X500 last week. I bought it because of the hardware spec, mainly built in GPS & WiFi & phone. I have had palms since the original palm pilot, and once went to the dark side and bought an imate pda2k. I very quickly went back to palm and a treo 650.
However, my memory is bad and the thought of a GPS built in, giving me traf cam alerts had me excited.... Doh.. how wrong I was. It is typical windows. Slow, counter intuitive, takes so many clicks to change anything, and best of all Tomtom crashes with 30 secs of it starting. Oh and Tomtom were about as helpful as a chocolate teapot ("Your device is not compatible, sorry"). I'm hoping Co-pilot live might work.
If you like Windows mobile PDA's then this could be for you. If you are a palm user then I would stick with your existing product until palm come up with some decent hardware.