I've got the Harris/Larue QD 6-9" with notched legs & cant. The Larue QD mount is a must, even if you don't move it between rifles ( I use mine on several rifles & a .223 pistol) it's nice to quickly take it off when not needed. Shooting from a bench I think the longer (over 9") legs will bring you up too high, I usually only drop down to the first or second notch. Which is why the notches are great, you can deploy to the same height every time, less fiddling. The swivel cant was kind of a PITA with a top heavy upper, it seemed to fall over all the time. But it can be locked down so that's how I leave it. I've also got a set of TangoDown/VTLOR bipod legs (the ones that attach to the side of your quad rail) I picked up used on my big scope upper. That setup has a wider stance than the Harris and attaches at the front of my quad rail so it's more stable side to side, and it keeps my bottom rail open. TangoDown also makes a bipod that attaches underneath that also has side to side swivel, which I would probably use more than the cant movement of the Harris.