From what I've heard the Hilliards have nicer bronze bushings, but in my own experience Max-Torques do the trick just fine for 20ish bucks. Mine's been used and abused very hard for somewhere around 30 to 40 years by kids out in the country and now me, and it runs like a champ! As with most clutches I have to oil it periodically, but hey, it does the job just fine! It actually is more reliable than the sprag starter clutch on my Briggs lol.
From what I can tell the Hilliards are mostly just more expensive. Another thing of note is that Max-Torques actually have how to disassemble videos, only one clutch spring instead of 4 or 5 smaller ones, and upgraded springs are available for purchase so you can customize the stall speed to be lower or higher.
So in short my opinion: I haven't used Hilliards, but if you want to pay a little extra, their Extreme Duty clutches oughta hold up pretty well to general thrashing. For performance oriented stuff I recommend the Max-Torque SS (Six Shoe), almost entirely because they can be rebuild and upgraded at home. IF you do go for the Max-Torque, MAKE SURE it's a genuine one!! There are actually a lot of fakes on the market!