I only quickly scanned other responses but here is what I found on buying my last unit.....
- Test drives NEVER show you all the issues for many reasons. Once you own it you become more sensitive to all the issues. I test drove my last unit and it was fine. Bought it and within 20 minutes was ready to return it if I could. The issue was the road noise I could not hear myself think when driving and it was not there before. Fortunately after I got out of town I pulled off and found a window had opened slightly, closed it and all was good (funny thing is that it still opens itself every once and a while and ticks me off as I hate noises).
- I also found that my unit was a wanderer, took it to a mechanic and they did an alignment, we adjusted the tire pressure and other tweaks and off I went. I cannot say if any of that helped but just driving it I got use to the feel and the response. Still does not drive like my SUV but then my SUV does not have a washroom and kitchen sink. I think most issues with handling are the fact that we have a new to us unit and just are not use to the feelings when driving.
I would strongly suggest that you take it to a mechanic that you trust and have them check it out. I took mine in and told the mechanic to look for anything wrong, only thing they found was the alignment was off and like he said with that much weight on it the alignment is good to check regularly anyways and after 150 kilometers it was time. After driving for a while I made some notes as to what I wanted fixed / updated and had that done (they did a full tune-up and the RV feels like a new unit). I have started another list and someday will take it in to have more updates done (thinking I will upgrade the suspension / new tires and rims) but that is as much making it mine as anything.
After several trips I do not notice a lot of the things any longer as I am now use to the unit, on the last trip other than the window opening I was shocked at how well it handled and with the low noise and that was even with having to do some emergency defensive driving thanks to some idiot that passed on a solid line!
Forgot one thing.....
When I bought my last unit it is a Ford E450 and I had not driven a Ford for years and no vehicle heavier than a 2500 and this is a 450. That in itself makes a difference as well. A different manufacturer and different weight will make things feel so different.