http://www.land-and-sea.com/marine/torque-shift/torque-shift.htm

think it really works? I've seen props you can "set" the pitch too... what about them? they work?

L & S torque shifter props have been around for a number of years. Do they work? Yes.  Are they the answer to the question "What's the best prop that gives maximum top end with a neck-snapping holeshot?"

Well, NO.  There's more to a prop than just the pitch (which is the only big difference with this prop, the pitch varies according to engine torque applied).  They're not the fastest nor the slowest.  While they'll certainly provide outstanding holeshot, it's the mid - to very upper end where they tend to have a problem.  Since most guys are looking for the maximum they can get out of the upper end of their boat,  the torque shifters have pretty much been ignored since the props really can't be modified properly.