Me and my wife looked at both. We have some buddies at our camp ground that have a 373RES as well and they like our 390RK but prefer their floor plan. For us it was two big things:
1. My wife did not want to come home and walk into the kitchen. We also really liked the wood wall behind the TV and the 2022 models added a mantel that we really like. Being the living room has a tall ceiling, it makes the living space much more roomy.
2. The rear kitchen model is great because we can cook with multiple people up there and the island is awesome. Plus, we can eat at the table and overlook the living room. We can easily watch TV while we eat and then we transition down to the living room to relax.
Another thing most folks dont think about is heat rises, so temp control is easier when cooking and the living area stays cooler.
A detractor is the heating and cooling. Since the 390RK living room is down a level, it does not heat or cool as well. If the ACs are kicking, then it is likely warm in the couch area. If the heat is on, then it is likely cool in the couch area. The other parts of the coach feel better in that sense.
If accessing the refrigerator while on the road is important, then it is more difficult with the 390 because you have to put out two slides to get to it vs one for the 373RES. I hope that helps and let me know if you have any questions.
