We had a 2004 Coachmen Mirada for just about 10 years. Never had a problem with the appliances or the Ford Chassis, but the Coachmen built stuff was pretty shabby. Carpet came up at the ends, constant roof leaks, cabinets coming off the walls, plumbing connections coming apart after a few years, the "waterworks" system had to repaired twice, and a constant flow of hot air from behind the gas pedal made driving in hot weather pretty nasty.
On the other hand if the unit you are looking at is a 1999, the previous owner(s) may have dealt with and repaired any issues.
In any event , best of look with which one you choose!
Doug & Mary Jane
2014 Bay Star by Newmar
2009 Subaru Toad
Ziggy & Maxi, the hounds
Retired and loving it