The F3 is not easy. The button is small diameter, sharp edged and strongly sprung, and must be pressed to move the dial any increment. Very secure as a result. The LX is better shaped, larger, softer sprung, and only needs to be pressed when moving off or past 0. It's possible though not easy to nudge it off a compensation setting. The ME Super has no locking button at all, the dial's edges are shaped so they don't get caught on anything, and the dial takes enough effort to turn that it requires a finger on either side.
I shoot manually, so it doesn't matter to me, but it's interesting to me that the ME Super lock-less design seems to work as well as any other.