I don't have any problems with signal on AT&T with my Moto Q. From Rhode Island to North Carolina, there are only (2) spots where I drop signal on I-95 and its only for 100M or so. I'm always on 3G and never on Edge, even getting full bars while on the beach on less populated area of Jersey shore. That said, the HTC TP2 on AT&T, had a varying signal strength, in all the stores I demo'd, where again my Q had solid 4 (full) bars. Could be the phone.
(2) weeks with the (2) different Droids on VZ, just driving accross my town I ran accross 3-4 dead zones, less then 2 miles from VZ store. I have the 3G->1x-> no signal while phone sits on my desk at home. Though I personally think its a Droid issue vs. network.
However I will be trying a GSM Milestone next week or so to see if I fair better.