What's the difference between the Ultra 4800R and the 4800RW made for Walmart?
Ones made for Walmart ones not. Not much.
There might be a subtle difference like say with the remote but
they are basically the same
There's very good chance the remote has a Vudu key, even through they sold it to Fandango. And it won't have Fandango Now Movies & tv section along the left side menu instead in will be just another app tile along with all the others.