Mine is a 2018 and it has been great for the year I have owned it. A little over 6000 trouble-free miles. I think the biggest difference is a better refrigerator/freezer in the 2018 and the touch panel controls. The touch panel is a mixed blessing; some things work better and some are more awkward to control.
Repairs so far have been one window shade motor. Airstream supplied the motor and I installed it myself.
We had a 2014 Lounge before. For only two of us, the extra two seats were not needed and used up half the coach.
John W. Irwin
2018 Interstate GT, "Sabre-Dog V"