We purchased a 2019 (2018 F53 Chassis) Winnebago Vista Class A. I am planning to add the Sumo Springs to the front. Should I also replace the OEM front shocks? The rig has 4900 miles. What have been your experiences?
At 4900 miles I doubt it needs it but in some cases it can improve the ride. Some chassis manufacturers don't always put the best shocks on but are out to save money. If you're looking to improve the ride then treat yourself to new shocks if you think it is needed. Koni's seem to be a popular upgrade.
The front "shocks" function as dampeners to reduce the movement of the springs and nothing more. Go with the heavy duty versions of the SumoSprings at the front and at the rear as they will reduce wheel travel and help with stability in turns where more than half the weight is carried by the outer wheels and springs. SumoSprings come in normal and heavy duty versions and I went with the heavy duty as the MBZ chassis is overloaded with the RV weight even before adding cargo and passengers.
I would doubt very much that Mercedes Sprinter shocks for their commercial van chassis are not well made. Replacing them now will accomplish nothing and is a waste of money. When and if it comes time to change the shocks I would look for adjustable ones (like the Rancho XL) so you can adjust the resistance and tune them for your RV.