At ~$250 the front Elka springs were worth the money, but the $650 Works Ultracross rear shock was not worth the money at all. The problem with solid rear axle utility quad rear suspension is the shaft drive, and the fact that under power the ring gear trys to climb up the pinion gear. So when you give it the gas it stands up on its rear suspension, and when you let off the gas it settles back down again. That effect really takes away from the responsiveness of the suspension over big acceleration bumps (whoops), and makes it tough to tune in the suspension so that it works good both under acceleration, and off throttle. Every wonder why street sportbikes still have chain drive, and cruiser bikes have shaft drive? Its because shaft drive rear suspensions start getting real funky as power output increases. And the stock Prairie 700 has this problem badly enough as it is, so when you double HP output with a big bore motor the problem just gets worse.

Your Grizzly has independent suspension at both ends though, which would I think tend to eliminate this problem, even though it still has shaft drive. I would suspect that high dollar suspension on your Grizzly would help alot more than high dollar suspension did on my Prairie.