Interesting question. There's pros and cons to having anything on the right/left side of the kit simply because the opposite hand is available to use the kit at the same time. So, left side china = I can easily hit anything right of the china with my right hand while hitting the china with my left. Right side chine = I can hit anything left of the china with my left while hitting the china with my right.
A bigger benefit to the right side is riding the china in some fashion is more comfortable because there's no one-hand-under-the-other going on.
I've used the 19" K China for years. I Love it.
Vinnie does a lot of cool things with the china on the left, my favorite being the GHUUUSSH (goosh?)..which is the floor tom and china together, makes for a unique sound when played loud or soft.
VERY START of this vid: You cant see it, but you can definitely hear it.
http://www.youtube.com/watch?v=22IWnwHjjGYOne of my favorite things he does is what I call "finessing the china" where he hits it quietly as a layer over a BD pattern...check around 2:55 here (link goes directly to right before that spot)
http://www.youtube.com/watch?v=O2fdN1uXvp4&#t=02m52s <== fucking beautiful.
Also he uses it as the "backbeat" during "Toast for Eli" for a slow type thing.
A On another note I think Neil Peart actually used the china on he right in some very cool ways, going back and forth between it and the ride on tunes like "Subdivisions" (outro), "Jacobs Ladder", "Between the Wheels", and "New World Man". Interestingly he used a Wuhan china during most of his career, he may have stopped when he switched to $abian.