It doesn't help with the performance per se. It allows you the rider to concentrate on your performance vs. worrying the clutch and back torque to the rear wheel. When I put my first slipper into my supermoto it made a noticeable difference in lap times. I was riding smoother and more consistently.
The Ducati Performance clutch looks like an STM. You'll need to pull the pressure plate, clutch pack, and the inner hub out to clean and regrease the balls and ramps. Don't lose any of your balls when you take it apart
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I don't know what the interval is. You'll have to RTFM
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to get that info. It's not hard to do. Should take less than 30 minutes to do.
To be honest, unless you are planning on a lot of track days, you may not find it worth the money. You'll have the extra maintenance and you also might see reduced longevity of the clutch pack. And at $200 a set it will add up over time.
But it is a hobby and one spends money on what makes one happy!