Re: Which Straplocks?
One of the things I love about the Dunlop Duals is that you don't need to connect the inserts to your strap. The buttons act like normal strap buttons. So you can pass on the locks altogether, or you can put your strap on like you would on a normal button, and then put the inserts on afterward, as simple retainers, like a high-tech version of the Grolsch washers. In taht capacity, the buttons are doing all of the holding, and the inserts act only as backups.
The main thing I dislike about the Schallers is that you need to dedicate your straps to being lockers; a strap without the clamps installed will likely fall off of the buttons unless the eyelets are very tight. If you forget a strap, you have to hope that someone else at the gig has a strap with Schaller lockers on it. And if someone asks to borrow your strap, and they don't have the Schaller buttons, you hope someone has the right size of wrench handy.
Another thing I like about the Dunlop Duals is that you don't need to orient the inserts a certain way on your strap ends, and you don't need a wrench to install or remove them.
Neither one has ever dropped one of my guitars.