I take back anything bad I've ever said about the Samsung Ace - it's not bad at all. A straightfoward, EVDO Windows Mobile 6 QWERTY Smartphone sounds fine, add in the fact that you can slap a SIM card in, reboot, and have it work on GSM makes it better. All the standard Samsung add-ins are here: their small apps, the jog wheel, the weird proprietary connector. Keyboard's a little clacky, but otherwise is second only to the Q9 in this category of YAQKWMS.
If I had to knock the Ace, I'd say the biggest downside is that the GSM radio is locked. Meaning that if you want to actually use it you have to set up a wonky international plan with Sprint. It would have been much better to just be able to purchase pay-as-you-go SIMs internationally. Hopefully getting this sucker unlocked won't be too difficult.