I am riding a 2009 SC Heckler with a stock rp23 light valved for comp and rebound. The shock has a high volume air can. My question is this: for the type of riding I do (xc/trail) what is the ideal size air can, high volume or med. volume? What is the difference between the two in performance? I am looking for good small bump compliance, efficient pedaling and climbing and a nice progression at he end of the stroke for when I do hit bigger stuff. Would I be better off getting my shock re-valved and or switch the air can?