We purchased a 2013 Cougar 327res. Love the layout. Took some getting used to not having all the drawer space we had in the class A but that was easy enough to get over with all the available cupboards and some creative organization. The touch panel has given us some grief from time to time but we have the work around down pat. Otherwise mechanically there haven't been any issues (knock on wood). This is our second full season and had our first tire blow out a few weeks ago. Wishing I would have pushed harder for new/bigger tires when we bought it but live and learn. We dry camp so the pull out bumper has been wonderful for mounting a generator box. Basement storage is ample. Not as large as some other manufacturers but plenty for what we need to haul right now. There are a ton of complaints about Keystone service and such but I have had pretty good experiences working with them thus far. Taking the "you get more bees with honey" approach seems to work pretty well.
The service department at our dealer is a tougher nut to crack than Keystone, truth be told. We pull the trailer with a 2014 Chevy 2500HD. DH even lets me drive. It is a pleasure to tow but we are generally flatlanders so I can't speak to what others may know about hills and mountains. Good luck with whatever you decide. Happy camping!!