Pretty happy with the interior build quality of our Sunset Creek, now owned by Winnebago. They used to have a very high quality rating, and one of the lowest employee turnover ratios in the business (ie, how long their employees stay there. Their average was about 11 years when others were like 4. Goes to build quality, pride of work, etc.)
We had a few issues with the unit, but overall is holding up very well for 8 years old. Built like a tank! But being aluminum framed walls and siding, is almost as light as a "lightweight". Has full actual I-beam frame (not welded I-beam) and 10,000 GVWR. My carrying capacity is over 3000 lbs., even thought I'll never tow it with that much stuff and this tow vehicle.
Not sure what level of quality Winnebago is currently putting out but worth a look. They used to have a very good reputation for value.