For woods riding, the more technical & slick the more it helps. It helps you keep traction on technical climbs because the clutch is being feathered consistantly. It also helps a bunch on log hops and other places where it's easy to stall or apply the wrong amount of clutch and/or throttle.
It helps when coming into a corner because you can brake slide without worrying about clutch application or killing the engine.
Manual --- still works as it normally does - you can hold it in and rev for a launch, or pull it to spool the engine up a little if you like. The auto clutch always disengages as the engine drops below the stall speed - the manual setup just manually disengages the clutch anytime it would be active (if that makes sense).
You can start the quad in gear - after starting, you just give it gas & it goes...
The manual clutch setup was a requirment of mine - I did not want a setup that completely deleted it because I felt I would still use it a lot. I've since found that I almost never use it unless I'm doing a hard launch (even then I'm not sure if it helps or hurts).
Problems -- It has been 100% reliable for me so far, not a single problem.. I know a couple people that have had a few problems, but all were traced back to their installation. Rekluse's customer service is very good & they helped those guys out even though the problems were related to the clutch's installation.
Installation is not hard, but you really need to pay very close attention to the instructions & not take any shortcuts. If you follow the installation directions well and also follow initial adjustment procedure - you're good.
Also - this is one of the very few aftermarket parts I've bought that fits correctly, has very good & detailed instructions, and has plenty of spare parts to cover any issues that might arise during installation. I was very impressed the whole time I was installing it at their attention to detail. They are quality people in my opinion....