Most manufacturers built entry level, mid level then upper level 5th wheels. There are a few models above even these upper level 5ers. The very top three are all custom builders. They are in no particular order 'SpaceCraft, New Horizons, Continental Coach'. These are very heavy well built rigs that require the F-450/550, Ram 3500 with all the towing options or better yet a Freightliner Sport Chassis type Mid Duty Truck (MDT).
Then probably next are Excel (just went out of business) DRV, Lifestyle, Luxe. The Augusta Luxe is the latest to the up scale mix.
Then to me the Dynamax Trilogy, Holiday Rambler Presidential are probably next.
Then there are over a dozen other manufacturers that build more 'run of the mill' 5th wheels. 5th wheels names like Montana, Infinity, Pinnacle, Cardinal, StoneRidge, Brookstone, Bayhill/Alfa Gold, Landmark, Columbus, Solitude, Redwood.
You have to do your homework to figure out which one of these 5th wheels are better then the other. All are probably ok to full time in.
Things I would look for are 7,000 axles (8,000lb axles are better) 'G' or 'H' rated tires (not 'E' rated) a thick 12" I-Beam Frame (stacked box frame is better) flush mount dual pane windows, and one that advertises good insulation.