Switched from comcast to directv last september... pretty happy with it overall. They always run sign-up specials, where you can get a dvr thrown in for free,or maybe even get basically every single channel for free if you buy the NFL ticket package (which is like 90 bucks a month for 4 months) --- this is what wegot last year, very happy with it. Then we cut our package back to some more basic thing, but it's still pretty good.
Signal has never gone out since we got it.. we get all our locals still except for like public access stuff.
Don't have anything HD yet, so i can't comment on that.. but i know they offer a ton of HD programming.