Great conversation here. I registered in the rewards program with a HTU in the Richmond VA market a couple of years ago at the urging of the store clerk. She said how the program rewards with discount coupons and it was a great deal. What she DIDN'T tell me was that it tied into that store only, and my purchases at other stores didn't count towards my rewards.
I have a HTU here in South Charlotte that I stop in because here it is either there or Hobby Lobby. The prices at this HTU seem to mirror those of Modelroundup or Tower Hobbies online, so not too bad. The guys there are pretty friendly and while the selection isn't great (and has shrunk recently), they do have the occasional new release priced decently enough that I can justify the couple of bucks difference.
I do use them for the Evergreen plastic, Tamiya colors and occasional kit, but also shop online or at Hobby Lobby.
There is a HTU about 25 minutes away and it has a new owner who seems to be energized about the place but his kit selection is pitiful and is priced at straight MSRP, so I doubt that I will be hitting him up until I see some improvement. I do stop in and buy my Model Cars Mags there and also some paints too.