Dunlop seem to be the overwhelming industry standard (they come on Sadowsky's, Ken Smith, MTD, Fodera, I think Alleva's now).
I really like the Dunlop 'dual design'. You get the Dunlop system imbedded in a standard strap button, so you can use a regular strap if you forget your 'dunlap loaded strap', etc.
Wonderful, and I've never had a failure with the Dunlop in decades of using them.
...but if something bumps the spring clip retainer loose, or it just plain wears out, the instrument is on the floor.
Saw it happen to my guitar player, and as I said before, it damaged the guitar (snapped the G tuner clean off) to the point where he had to switch to his back up.
Thankfully, he is smart enough to bring a back up.
The Schallers work fine with regular guitar straps too. My 89 Fender came stock with them, and I've never used the locks on that one, just a regular strp.
