Grand Design has the same "stickie" construction as most and the same basic problems in terms of having lots of seams (plus thermal bridging from the aluminum studs, though they have very good insulation between studs).
They do have two major advantages, though:
1. They QC every single trailer, not just a small sample. This sounds like it should be the default, but it isn't.
2. They seem to really go out of their way to honor the warranty. Probably fairly equivalent to
Bigfoot or
Escape.