I actually don't like the idea of leg restraints on X2. Although, yes, there is that one major rough spot at the bottom of the second raven turn, it's not unbearable; especially when you know it's coming. Other than that moment, I can't think of any other portion of the ride where it's uncomfortable to let your legs flail about in the ride. In fact, I think that's a big part of the thrill!
On a side note, I've noticed that I can move one leg across the seat so that both are on the same side, and I could, maybe, just maybe, slip out if I really tried. Obviously, I wouldn't try, but this happened to me on the last fly-to-lie before the brakes.