I have a Tour 9630 (its on U.S. Cellular) and the device is fantastic. THe 9650 is going to add the optical trackpad to replace the physical ball and a faster processor. Honestly I have had no problems with the trackball and the processor is fast enough for me. Signal is great as well (3g around here is solid). Although only CDMA carriers are selling the device it has quadband GSM, as well as GSM 3G, and depending on the carrier it may be unlocked for a sim card.