I have been using XM in multiple vehicles for years. Most of my usage has been via "FM" broadcast from my XM receiver to my car's radio. Most often this has been satisfactory for my "old" ears. Occasionally I do pick up some static and either switch XM channels or resort to CD or regular broadcast FM.

IMO the problems you are having may be your antenna placement. You said, "I could be driving down NY Ave past the big satellite at "XM world HQ" and have bad static." The XM broadcast to your receiver is up in the sky not in a building. Tall buildings, tunnels and mountainous terrain can affect your ability to receive clear signals.

I would go back to the Circuit City that did your install and explain the problem to them. Have them check and calibrate the antenna. They may have incorrectly placed or oriented it.