Dunlop strap lock user here. I have got them on both my guitars.
My experience with them is that they lock well, so obviously they do what they are supposed to do and I have a peace of mind when I gig. But beyond that I have several complaints about it. Firstly it's rather difficult to install the bit that should be attached to your strap. Removing it is difficult too and I have had sore fingers doing so. Secondly, the metal seem to tarnish rather quickly. Metal Polish didn't help much.
I'm looking at LOXX strap locks from city music for my third guitar. They look kinda pretty, hopefully installs easier than the Dunlop ones. And as someone mentioned, having a pull-release mechanism seems less likely to accidentally disengage the lock than Dunlop's push ones.
Last advice, while changing your strap pins and you find that your screws do not fit the guitar, do not think of re-drilling first. For my guitars I managed to find the screws with the same screw thread that can fit the new pins. The screw threads are pretty standard so you should not have any problems finding similar ones at a hardware shop.