I have had two hitchhiker's (not the discover America series though) and was very satisfied with the trailers and the service. My husband and I fulltimed in both. The only feature that we didn't like was the cable system for the holding tanks. On the last trailer it was very difficult to get the handles in and out. We also have friends who have had a hitchhiker for about 10 years and pulled it all over. They have had no complaints.
Hey bob-o, welcome to the forum. We have been RVing in a NUWA HitchHiker II for 13 years and have been satisfied with it. I would say that the Carriage, NUWA (HitchHiker/Discover), Excel, SunnyBrook, Alpenlite, Gulf Stream, Montana are all in about the same price range and are made for 4 Season RVing (fulltime).
I stayed in a NUWA Discover America in Yuma this past winter and loved the floor plan, 33 four slide, and loved it. The only thing that was a challenge was the bathroom floor was soft. I had a moble tech come and look and he said that there was no signs of water damage, but after taking the heat register off, the wood for the floor was only a 1/4", a little weak for me. But other than that, great trailer. Happy Camping!