You will probably get dropped calls with most any service, I have friends on VZ and they get dropped calls from time to time. I have very good service where I live/work and rarely get dropped calls. I mostly get them when I drive in and out of 3G coverage.
My experience with AT&T CS has been very good. I had an issue with my bill. Can't remember what now, but they fixed it to my liking and have always been very helpful when I have called.
Of course being nice to them up front always helps you get your way also.
