We just bought a Grand Design Solitude 375RES, after four bunkhouse fifth wheels, we were ready for a rear living room unit.
Very happy with the unit, fit and finish is excellent, the appliances, furniture, lighting, and overall build quality is excellent. On the outside the decals, the roofing, and again the fit and finish is excellent. Lots of personalized service from our dealer as well as calls from the factory rep during the buying process, and after as well.
I like being part of the "Grand Design Family", lots of positive feedback on many rv sites about excellent customer care/service after the sale be it a Solitude, a Reflection, a Momentum, or Imagine.
Not so sure this can be said of Montana, part of Keystone, owned by Thor. There was a nightmare of a thread about a Montana a while ago and another currently about an Avalanche by Keystone.