Device reception is fine, at least when calling a land line. Calling other cell devices, that is variable. It has nothing to do with the Z10 phone or any other phone. The biggest issue, whether it is 2G, 3G, or 4G or whatever, the call quality has more to do with the provider's equipment. If the transmission is stifled by the quality that is available with the transmission then the connection is going to be marginal. All carriers have this issue. They need to upgrade their transmission equipment to move data better, but, they don't do that. Don't blame the phone.