The Kwaiken Button lock is a nice idea in theory, but poorly executed. The grind is uneven, the centering to the right, the lockup is light and fails under normal pressure, the "bearings" are plastic washers with the worlds smallest bearings in them making for a stepped feeling action, and worst of all the button is taller than the scales and even the pivot with a light spring. This leaves it very easy to accidentally disengage the lock with palm/finger pressure depending on the grip.
I will give them credit for a button lock that feels smooth, albeit it doesn't always actually securely lock, really nicely milled premium scales, easy disassembly, and using a premium steel, although the MSRP is a bit unattractive, if you could manage to get a flawless version for around $139 it might be worth it, unfortunately mine is both a lemon and the button is too tall, making it largely unsafe to use for any adult sized hand or any grip that may apply pressure to the plunge lock.