I've had it with the MPx200, and I'm going to be returning it to AT&T, thanks to their 30-day refund policy. It's a cool phone, and it has a lot of interesting features, but no matter what I do, it won't last longer then 8 hours before the battery dies. I've deleted every program that I installed, removed the SD card, replaced the battery, and it still runs down its battery astoundingly fast. Cool is nice, but it's got to be a usable phone. And a phone that's dead isn't very useful.
Plus, the PocketMac people still haven't been able to fix my sync problems. As it stands, I need to reboot my Mac every time I want to sync the phone. Allegedly they've handed me off to their "driver guru," but I haven't heard anything from them since then.
So, what am I going to do? I have no idea. I've been tempted by the Treo 600, but it's over $300 more then I paid for the MPx200, and it has a lousy LCD display. I've had Palms with 160x160 displays before, and I don't really want to go back there again.
So, I'll probably get their cheapest Bluetooth phone (this week, it's the Sony-Ericsson T616) and start looking for a new PDA. I'm leaning towards the Palm Tungsten C for reasons that I'll explain shortly.