Post Master General
Join Date: Apr 2012
Location: Bowling Green, VA
I Ride: '09 ZX6R
A random eBay shock is not likely to outperform your OEM shock. If it does that's blind luck.
Even a name brand fully adjustable aftermarket unit will perform better with a service, the right spring, and correct set up.
The most right answer will be having the suspension at both ends set up for how you will use the bike.
Whether that's with your shock or another, is up to you.
"Basic stuff fellas. Use your head for something other than to break your next fall."