Sorry, I got sidetracked there and cut myself off short.
What I want to convey is too things:
1. Don't believe the hype behind any product (either than the C2)
2. Assess your goals and apply the methods suitable to them. KBs will make you stronger but if you want legs like tree trunks then you will need a bit more oomph in your training. Don't forget that distance runners have pretty strong pins but they may have a different kind of build to that sort by another trainee.
I very really squat with a bar (read almost never) because I don't have a stand and I can't rack the bar properly for front squats. I train my legs with db squats, step ups, lunges, OHS, deadlifts, powercleans, db snatches, skipping, running, sprinting, cycling etc. My legs are strong enough for what I want them to do but I'm no Austrian Oak. And that really doesn't surprise me.