Hey. I've run 4 different frames with various shocks including the RP23. Not recenbtly but in the past. You will transform the back ends action. Your rear shock determines handling characteristics for the whole bike, if you can get a good deal go for it and sell your old shock right away as it will depreciate in value.
If you run the shock for a year or two it will offset the cost of it with the use you get, minus the amount you get for your old shock when you sell it. 2 years of perfomance enhancement and every time you ride it will be much better.
I sold an RP23 with bushes to fit a Turner 5 spot that was running a Romic shock. The guy ray said it was like a completely new bike. You will see less benefits from him but you will know the difference.
Ridefree!