I'd be a bit of a sceptic to using it on gravel, but won't know if it works unless you try.
It keeps the rear from rolling, and adds more lateral force to the tires, which isn't really what you want on slippery surfaces. LRC gives you more roll, and more vertical force down on the tire, which could give you more grip. But then again, coming from touring car racing, I've seen this go both ways, so please do try!
And as Gnarly says, it keeps more consistently! On midmotor I've been running HRC mostly, but with the rear motor, LRC seems to be they way to go. But it depends a lot on grip levels and bumps. On a bumpy track, HRC is a no go for me. But that is my experience from Astroturf, on clay I've only used LRC.
But then again, a good thing for rear grip? 15-20 grams of weight placed on top of the gearbox, just behind the shocktower. I used a mid weight kit, and cut it to fit there. Also that then becomes the perfect place to tape your power cap
