I've run a PowerTrax No Slip Traction System (https://www.powertrax.com/product-info/no-slip-traction-system/) for the last 14 years or so, it's bulletproof and definitely gives full locking, but it's a bit of a pig, makes low speed maneuvering difficult, and worst of all has a ridiculous amount of backlash, I'd say at least 1/4 turn of the tailshaft worth. Maybe I'm getting old and want a more compliant ride...
I've looked at the WaveTrac and it looks great too (as is all of Ben's stuff, got some on the way right now actually) but the price is just too much for what I want to spend.
I've heard a lot of good things about the TrueTrac, based on what I've read it's not quite a 50:50 locker, but I'm willing to give that up for a smoother and more silent ride.