These straplocks are great. I have them on all my guitars, and I've never had them fail.
I like this system a bit more than the regular setup, where the lock put on the strap knob with a hook-like system.
This seems to make a bit more sense to me, as you lock the strap INTO the knob, and you can't pull it out with out pressing the button.
I would recommend these over any other strap lock on the market right now. Or at least something like these, with the same system.