the cellular network is a honeycomb network. The number of base stations wrt load and coverage will affect line quality.
the red one being the oldest around, has one of the most base stations. I shall not go into details about building problems and their barriers for housing base stations; the difficulties involved in buying/begging the space up there, but just take it from here that red has very wide coverage. the other two brands are just expanding.
But if you live in a private estate with rather sparse population and is very near to a base station on a commercial building, chances are, you will get great signals no matter what brand you signed up with.
Also, operators are supposed to "monitor situation" :bsmilie: and put in more base stations in the event most of the lines are filled up with aunties and xmm jamming the phone lines.
As for data, it operates on d channel and hence the voice channels should not degrade line quality at the backbone. It can all be improved, but its about economy of scale and feasibility sometimes. So, if only two person complain, do you think they will move the base station closer to you or install a new repeater for you? Perhaps not. They will kindly tell the complainant to suck thumb and die.:bsmilie:
