When I first realized my old TV was getting all the stations just fine, I took it in the main room where the new Continu-Us TV was located and hooked all the same cables, etc. up to the old Sharp TV. That way I knew the only difference was the TV's and not the cabling.
But I do agree another big part of the problem is the omnidirectional Winegard Roadstar. An omnidirectional antenna cannot possibly work as well as a directional antenna, especially in fringe areas.
I'm still considering a KingJack antenna, which can be rotated like the Batwings. I just hate mess around with more screws and re-sealing things on the roof.