I love mine!!!
I've got it set up so that on idle it wants to go, rear brake is required on slippery surfaces otherwise it'll slip the wheel a little.
I prefer it this way so it picks up better on the gas! My mate had his set to the opposite so it slipped more but mine was quicker off the mark.
It does work as a slipper clutch to some extent. It removes the rear wheel chatter and means you dont have to feather the clutch which has gotta be good as there is less to do whilst racing supermoto.
I played with several install gaps till i got what i liked and basically ignored the install gap instructions. Try different plates and see which combination you like. Worst case scenario is a stall or no drive at all.
I'm gonna get the adjuster to use the manual clutch too then i can hoist the front wheel in higher gears if i choose.
I've got a YZF450 too. Can't ride it without its that good!