My apologies here in advance.
I watched that video and was not impressed with the E350 and E450 J-Ride. I am sure their add-ons do good, but I feel those extras are band-aids rather than real improvements. There has been so much discussion on how to make a Ford E350 and E450 handle best so I won't get into it again here.
Regarding the sagging issue the video mentioned, I feel the right solution is to go to the right place and get an OEM leaf or two added as needed to eliminate any rear end sag. Installing a contraption like Helwig helper springs may work, but why solve a sag with such a thing?
About the balanced drive shaft, that is supposed to be done by every Ford approved frame stretching company.
Isn't every RV manufacture utilizing the rubber mounts that are supplied by Ford?
Every E350 and E450 today has a front and rear stabilizer bar. They don't mention that they are replacing them with better ones.
Am I missing something? It sounds like they are stating standard items as a special package. The only exception would be the Bilstein shocks and that Helwig contraption.
What does the J-Ride package cost for an E350 or E450?