I'm a Montana fan, but the issues they had in 2002 included some frame flex in the long nose that caused some weld breaks on the frame below the bedroom walls, they were typically under axled (6k I believe) which limited payload, and the roof was flat with a raised floor in the bedroom which made it a little bit of a low ceiling for tall folks. Generator cabinet would only accept the microlight size generator because the door was too short.
They were a handsomely equipped 5er! We would have had one but they stopped making them when were were looking, and then restarted making them after we bought our 2007 (a month after).
Do yourself a favor and check the trim at the bottom of the bedroom wall both setting on the landing gear and setting on the hitch with landing gear retracted. If you have movement of the trim, you could have problems with the welds in the belly.
Not saying some movement may not be normal, but excessive movement would deserve a check of the welds underneath.
The walls are supported with plates spot welded to the bottom of the upper frame. If they are broken, it gets ugly inside in a hurry. (walls cracking, closet doors crush, general self destruction)