Both are fine coaches for their place in the pecking order of model lineup. Not entry level, and not top dawg either
Discovery owners are a loyal gang, and they have one of the most active owners groups around.
Same can be said for Newmar as a manufacturer, IMO, being happier as a group then all up Fleetwood (Minus American Coach, which treat separated then Fleetwood.).
OP - If buying new, I'd give the nod to Newmar. Even if it costs you more money. Ordering from the factory, and taking factory delivery, is a plus. When ordering, Newmar will work with you on reasonable modifications to the coach, to make it more customize to what the two of you want. And one other plus to the Newmar, I believe it includes Comfort Drive(?) - a nice feature.
If buying used, then it would be condition, condition, condition
! And I'd take condition over rock bottom price.
All that being said. Even though we all quite often read about 'Buy your last coach first!'. It really is difficult to do, as it takes sometime in RV'ing - to determine what you really want
! So, unless your positive that these two coaches are 'The one!' (And for sure, great if it they are.), you might want to consider looking at some used lower purchase point coaches. Go out and use them for a few years. And along the way, both you make notes about what you'd want to be different in your next coach. (You may find you want larger Grey/Black tanks. Or more power to to pull mountains. Or higher CCC capacity. Or more, or less, slides. You may want Jake Compression Brakes vs Exhaust. You may want side vs rear radiator. You may want a tag for added stability and again CCC. You may want.... Etc.)
Then go out and do your search again, and get a coach for the long haul.
Best of luck to you, have fun,