Using this on the T-MOBILE network in Southern Cali area.PROS:Excellent construction and build. Strong beefy metal hinge. Flip opens and closes without any creaks. Has a substantial "feel" to it. Even the battery door is made of metal (magnesium or aluminum, can't tell). Bottom part of phone also has rubber coating.I have small hands, and love the slim form factor. Folks with larger hands may not like.When getting a strong signal, call quality is excellent. I have both SPRINT (ppc-6700) and T-MOBILE accounts. Sprint has much better reception here in the SoCal area, but when the KRZR K1 has a strong reception, the call quality is crystal clear. Nice responsive 2MP camera. Decent MP3. This phone uses the ATI Imageon media chip.Stereo bluetoothCONS:Stupid name. The folks at Motorola need to learn how to spell.Phone is slow. Not super slow, but slow enough to get annoying - especially when one has a large phonebook. About the same speed as the RAZR. Phonebooks with pictures makes it even slower. For those that like a phone that is responsive, you may want to look elsewhere. No standard audio out jack (no 3.5 or 2.5, only mini-usb).Front of phone is a fingerprint magnet.Screen resolution too low for a "flagship" phone with a 2MP camera. Browser is slow.