We just looked at both of these and chose the redwood. One thing that concerned me on the Gand Design was the old style wood truss roofs. If you go to their web page you will notice you don't see much info on construction. The same dealer sold both when ask they said the high end Solitude used metal but would check, called the factory and said they were wrong wood trusses. I think both brands are good quality. We thought fit and finish was a touch better on the Redwood but liked both very well. The better warranty was better. All our research said Redwood has been awesome about standing behind their products. You can say the same with grand design, seems like they back their trailers well.
The tire issue has nothing to do with the trailer, every manufacture uses some brand of tire, some Chinese, some good year, some Japanese .... Don't see how that topic has anything to do with the quality of the trailer.