I think it is a smart move to buy used at this point in time. I'm betting the Nash is setting a pretty high bar for you.
I have a 2018 303RLS and wasn't familiar with the Wildcat's floor plan, so I looked at them online. I have to agree with the other posters - it's about what floor plan suits you. My personal reason for selecting the 303 was that it has lots of window area - on the curb side - including a huge back window, and that the TV is directly across from the recliners. I see that the Wildcat puts the TV in front of the back window - maybe it descends into the cabinet below? But the recliners are at a right angle to it.
As far as cold weather camping - who knows? Not sure about the Nash, but when RV's are advertised for "Artic" conditions, I have to laugh. They are not insulating with closed cell spray foam - and the walls are thin. So it is a tossup.
Quality? Who knows, but any quality issues on used units this old should have been exposed and corrected - although I agree that the GD was built when that company was newer and you may be surprised. And as seasoned RV'ers, you likely already know how to determine condition - check for leaks, check the roof and tires, etc.
I'm curious as to the condition of the recliners in the GD 303rls - has the fake leather started flaking off?
So in the end, go with the floor plan you like best and then pick it apart with a fine tooth comb. Good luck.
