I am on my second Keystone fifth wheel and am have been happy with both. My Keystone Sydney is about the same design and price level as the Cougar. All RV makes and models have their quirks and bugs to work out when used or new. The key is making sure you are 100 percent satisfied with every square inch of the unit before you sign the papers and leave the dealership. I recommend that you check out this forum:
Keystone owners forum Lots of good first hand info from Keystone owners and the site is not monitored or owned by Keystone. There is a good PDI checklist there as well that you should download and use.
Steve Rinker
Rochester, NY
2013 Keystone Sydney 340FBH 5th Wheel, 12,280 lbs loaded (scale)
2015.5 GMC Sierra Denali 3500, SRW, Duramax, CC, Payload 3,700 (sticker- not scaled yet)
Take my posts for what they are, opinions based on my own experiences.