I fall in the stock is good camp. We have a 2007 26.5 Laze Daze on a E450. Others might find the ride a little tight but my every day car for the last 12 years has been either a 03 or 06 MINI Cooper with the upgraded suspension - a car that rides very tight.
I think the E450 handling could be improved with mods, but I am mostly happy and I am not willing to spend the money for the small increase in performance. If I lived in the mountains I might be of a different mind. When the current Bilstein Shocks ware out I may make the change Koni Shocks. I am intrigued by the FSD technology but have not done enough reading to be sold yet.
The Chevy might have a better ride but it is not offered with the RV that fit my style of camping.
John