Welcome Charlie to the MOC Family.
There is little that I can add to what already has been said except to reenforce the fact that ALL manufacturers have their problems and I hate to admit it but our beloved Montanas are not exempt. Our rig is 16 months old and we have had only 1 problem and that involved a sagging shower door. Not too bad considering we are fulltimers and live in our rig 24/7/365.
As you have no taken delivery as yet I would like to suggest a way of reducing the possibility of any problems. Here is a link to a
PDI (PreDelivery Inspection) Checklist. Print this check list and take it with you on the day you pick up the rig. Using this check list, go over your new rig with a fine tooth comb. This is a very time consuming project and you quite possibly may not find a problem But if there are any now is the time to find them while still sitting at your dealer rather than after it's sitting in your driveway or set up in that first campground.