I'm on my second Georgie Boy, had a 1990 gas Cruise Master for 10 years, traded on my 2000 Landau Diesel. Both units have served us well, and overall were better than average quality. My Landau is on the XCS chassis. The Cruise-Air is probably on the XC chassis which was Freightliner main RV chassis. Probably closest to the XC-R in the current models.
Air suspension and exhaust brakes are normal. I believe Cat engines are no longer an option.
Motorhomes consist of an assembly of various components, and heat, Air conditioner, fridge, furniture, awnings, holding tanks, even slide outs -have basically the same few manufacturers in all RV's. Newer heated tile floors, aqua hot and self storing awnings seem neat but also have their share of problems.
Overall layout, good maintenance records, and upkeep are important in a used RV. As born2travel stated- most of the bugs are taken care of early on..