May buy this trailer and need comments

While I can't advise you on that particular model, I can say that what is more important is the actual pin to rear bumper condition of the unit.. The Montana line as a whole is the number one selling fifth wheel for a reason. It more boils down to how the unit was cared for. A good walk through, especially the roof, caulking, etc should tell you a lot. I am super anal about every detail on my rig, but many people aren't. Most dealers do not spend the time to go through and detail every item and they will tell you that they did. With used, you buy what you get so look carefully and compare before you buy. Make sure to download a RV PDI checklist (Pre delivery) and review it before you get serious about a particular unit. Follow the checklist to a T before $ changes hands. You can find a good checklist here: Keystone owners forum

Good luck
Steve