We have an '04 Coachmen Cross Country that has the 300HP Cummins. I am guessing that this is older than you are looking for but I can speak to their quality from my experience. In almost two years of owning and using this coach, we have zero complaints and zero problems. Everything works as it should and still looks great. The engine? Well...more is always better IMHO but it does just fine even towing. A long grade will slow us down for 5 minutes but the other 98% of the time it cruises along at whatever speed I desire...usually 65ish.
We didn't have a budget of $100k at the time and I don't think we use it enough to justify that expensive of a rig for us. All of this said, if $100k was my budget, I don't think I would buy a Coachman. Not because Coachmen is bad but rather because you can get a REALLY nice, much higher end coach for that that money if you shop used.