One more consideration: if you can, find a store where you can stand up playing an RG and compare it to an S, then try them sitting down. Then evaluate how you spend most of your time playing.
The body shape difference is REALLY night and day. I've never played an S standing up, but most folks seem to swear it's incredibly comfortable in that position, almost like it's not there. When I tried it sitting down (i.e. propped on one knee), I couldn't get used to that feeling; it was like I was trying to play a credit card, and didn't know where to place my hand and forearm.
YMMV depending on your build. But body comfort is an important factor to consider, so check it out if you can.