They are essentially 4 little dogbone inserts that require less torque to put in. SOOO EASY. The rear feels more predictable and planted in long sweepers. I also don't get the "clunk" I used to get when I shift hard and quick (I have a manual with a springless 4 puck clutch though). I'm going to say its a no brainer for $99 shipped.
I used ramps, pry bar, impact gun, torque wrench. Took me about 20 min with waiting for blue loctite to dry a little before zapping in the bolts.
note: Do one at at time! Do not remove all the bolts at once!