Flarp.... Sprinter 3500s (with duals in the rear) only have al-you-minium wheels on the front and OUTER rear. The inside duals are steel. If they have the shiny, blingy, high shine wheels, they have 6 steel wheels. The shiny bits are stainless wheel covers.
If you had a 2500 (4 wheels) the aluminum jobs are smart and snazzy. According to some, the AL ones may be a couple pounds more weight than steel. But they do look cool and are functional. Having 4 Al and 2 steel, in my opine, is not my cup of tea. Six steel is mo' better.
Criticism about the stainless covers focuses on their shifting on the steel rim. When they shift they damage the valve stems leading to a deflation ... usually at the worst times. If the cover's little grippers are properly adjusted they will stay in place. Or, you can band them to the steel wheel with stainless wire ties.
We had aluminum rims on our 2500 Ventura and, now, covers on our View. No issues with either set up. I DO make it a practice to thoroughly 'pre-flight' our RVs before and during a trip. That includes very close inspection of tires, sidewalls, treads, inflation, temperature (IR gun) AND the position of the covers on the wheels.