I'm also playing the game, but I'm doing wrap-up in Omega Ruby at the same time, so progress is slow. I've got more than 450 different pokemon in OR right now, and every single legendary that existed before Sun and Moon was released, as well as all Mythicals except one. I've got all pokemon that can be captured in OR except one, which I'm still trying to get (damn you Mirage Spots).
As for Sun and Moon, I picked Moon as my game. On the second island (which is much better than the first) and enjoying it. My pokedex is up to a little above 60, and I'm planning to catch'em all. With the upcoming January update to the Pokemon Bank that keeps track of your National Dex, I'm going to make a serious attempt to catch every single pokemon ever released, and trade those that are impossible to catch in the games I own in the series (White 2, Omega Ruby, Moon).
The quality of life improvements in Sun and Moon are a godsend. It's nice to no longer have to keep a spreadsheet with strengths and weaknesses handy at all times, and the complete removal of HMs means I no longer have to carry around two almost completely useless pokemon just to be able to traverse the map.