I have used the RMA service twice now, shipped express, they receive and ship same day express. ship Monday have a replacement on Wednesday
Best support ever in my opinion.
Did you get brand new boards (4813) or used boards?
the boards had thermal paste on them and they were tuned nicely

speculate how you will.
I think they actually now test the rma boards, so they all come with thermal paste.
Someone sent me photos of the two boards he got back when he rma'd - oxidation on the vrms and residue round the power connector - obvious signs of previous use.