2009 montana falling apart 1 piece at the time

The best
New Horizon, but be prepared they are not cheap like your Montana, look at well over $100K. Floor-plan, you design it (I mean that, you design it with them to get exactly what you want)
Below that Excel by Peterson but still well above anything Keystone ever made, as is Mobile Suites DRV.

After you've had some time to recover from sticker shock, ask about affordable, good rigs