We just purchased a 2020 31UL in May, we've had it out twice and will have three more trips by the end of October. So far we are loving it. All systems are working just fine. We heard about handling issues so we had some stabilizing thing added before we even took it home (sorry, I can't remember what it's called). Both of us drive it and it handles just fine even with 2 semis passing us at the same time. We tow a Honda Fit and you wouldn't even know its there. The layout is perfect for us.
Someone mentioned the hot water tank, its 10 gallons.
We just received notice that Jayco has a recall on the generator timer, its not keeping time correctly. Our dealer has the part ordered for us. We've only run the generator maybe total of an hour and the timer reads 22 hours.
If you are purchasing new, buy your unit in Washington, since that is where your warrenty work will be done. If you are purchasing used it doesn't matter as much.