2018 3113 here. We haven't had any major problems. What we have had go wrong, very minor stuff, Newmar took care of. Love our rig. Still looks virtually new after 3 years full timing.
We didn't order the over cab bed. We do, however have an upgraded chassis, 22k to 24k. For full timing, it's been great. We still have 1500 lbs of cargo capacity. I believe being way underweight, the bigger springs, brakes, gears, etc. contribute to our great ride and handling. Never felt a need for suspension or steering upgrades.
2018 Newmar Bay Star 3113 - "Chewie"
2014 Jeep Wrangler Unlimited Rubicon - "Battle Born"