Rollover is the shizniznit (especially when your nite minutes start at 7pm instead of 9). I went like, 2 months without talking on the phone before 7pm and had damn near 3000 daytime minutes.
cingular, the rollover minutes are tyte and all, but the lack of service is not....
That lack of service could also depend on you phone. I just got a new v551, and I had a full signal all the way from Huntsville to Nashville last week (even in the mountainous boondocks in between). Hell, I can probably get a full signal underwater...