Serviced a M series 16570 in 2017 for RM22xx and the standard service includes change of crown and crown tube and polishing. Only RSC can refinish the bezel perfectly and even touch up the black paint on the bezel. I thought it was a new bezel until I saw the old nicks which were really deep. Turnaround time then was about one month.
in 2019, serviced a V series 116523 for just under 3k, also includes the standard crown & tube change, polish
I don't think price has gone up much but you can always call them up to ask what the standard charges are. I also think now that COVID is no longer and issue, they should be able to get back to the standard 30 days turnaround time.
the GMT movement is not particularly more complicated than a normal date movement
Wow! Didn't know they could just refinish the bezels and not straightaway replace them. Price seems quite decent too, although I hope turnaround time will be around 30 days only.
When they polished the watch, were the original bevels on the case edges retained? I've heard some horror stories from RSCs regarding overpolishing watches to the point that case edges were completely rounded off but also heard from others that they only do a very light polish. Would appreciate some feedback on that too 
Replacement bezel is a chargeable item. No need to replace unless badly damaged. Standard service include polish service and I believe no discount on the basic charges rate even if you decide not to polish the watch.
My bezel was badly scratched and the black markers were worn out. After polish, only one or two deep dings remained. RSC does not do laser welding. The unique sun-ray finish on the bezel is something most outside polish shops can never replicate. My initial thought was the bezel was replaced because it looked like new.
The bevels on the case edges and bezel are also like new. Something outside shops also find very hard to produce. Outside shops brush the bezel then polish the bevel till it's round. RSC bevels look like a sharp slice with very distinct lines. The brushed finish direction are also very well done around the lugs and and look like new. The watch has been safely stored away since service as I haven't had the heart to wear it since it's job has been replaced by the 216570. Will share pictures if I ever take it out of long term storage. Being the one and only time the watch has been serviced/polished might account for the end result as well.
As the 16570 is now getting quite old and soon approaching vintage territory it is common that owners want to retain it as original as possible. I think most horror stories of watches returning from RSC with a bad polish were probably already destroyed much earlier by outside shops. I don't think RSC can save a watch that is already over polished. Also, the expertise of the actual person working on the watch itself at RSC might be crucial as well.
