In general they are built in similar fashion.
To avoid the Lippert frame, you could go to the Pacific NW Builders, Arctic Fox and Outdoors RV, both are considered above average, and I believe build their own frames.
Others with loyal followings due to better than the rest of the pack customer service are likely Grand Design, K-Z, and Jayco.
Keystone and Forest River are back in the pack.
Some will disagree with the order I listed them in, but I dont think too many will go too far outside these positions with the only caveat being the higher end units from some Keystone and FR products may have slightly better Q&A than their mid grade and down units.
Happy hunting