Back in 1978 or so when I first started to play gigs, I never used strap locks...in fact I dont think mechanical systems were even marketed until a few years later. Back then though, the common gtr strap had big thick leather end pieces and were really hard to even get off and on regular strap buttons. I dont think I ever had a slippage problem and never dropped a gtr because I didnt have strap locks.
Then along came the Schall*r and Dunl*p strap locks and suddenly everyone had them. I had decided that the Dunl*ps were the better choice for me and there is a set on every gtr I own or have owned for the past 25 or so years.
In Sept 2007 I bought a JP6 and decided Id wait for the EB strap locks as I didnt want to use the Dunl*p longer thinner wood screw on this gtr. I bought a decent EB strap for the gtr and Ive done about 6 or 7 gigs with this gtr and I got to say that there has been NO issue with strap slippage at all. While the strap itself is not all that heavy duty, the regular EB strap buttons really grab the end tabs very well. Its a small design change with big results.
Again, at a gig Im not running around on stage or this big showman tossing gtrs in the air. Im a stand and play kind of guy. It just goes to show how you how much we automatically depend on certain "must have" items and how much we probably can do without them.
Irregardless, I really dig the idea that the EB strap lock screw is the same as whats in the gtr now thereby eliminating the need to re-drill or mod the screw hole, so whenever they are available, Im in for a set or 2. LOL. After all, the JP is a large investment and why take chances...