I rescently sent my SD 50th anniv for service, at my RSC, and despite the fact that you bearly get offered a bottle of water by the brand, they do make it up to you in efficiency.
I purchased my SD126600 in May 2017, and have been wearing as well as diving with it quite a lot. It resulted in some nasty scratches and dings through the years. Long story short, I sent the watch for a full overalling. Rolex service turnaround was am impressive 2 weeks, and watch came back looking new, on the top the polishing work was beautifully and skillfully done. I received the watch in a very pretty Rolex leather pouch, with a NFC warranty card. And that, is the new thing, you can read the card with the NFC function on your mobile, and it connects you straight to Rolex official page, and shows you, your watch history: ref no, serial no, all service history. Really, good move Rolex! I wish other brands could do that too...