MIMF

The title says it all, really. I've used it for joining wood for decorative carvings, and it works great, IMO. I didn't know if anyone uses it in place of epoxy for anything, maybe inlays or peg head veneers, something intended to be permanently fixed like that. It does adhere leather to wood better than anything else I've used, if that's useful to clamp/jig makers.

Not having ever heard of E-6000, I checked the manufacturer's website and learned that it "Dries to a rubber-like consistency". That may have some applications, but not many in lutherie, I would think.

It resembles rubber cement some before it sets, but it holds tight once it cures. I don't know its durability when/if under constant tension yet, but I made a small hammer with a leather pad for the head, and it did really good with the short impacts; how much was the glue vs. leather, don't know 100%, but there's been no peeling edges in 3 months. It appears to fill gaps well, FWIW.

Oh! E-6000 is an adhesive!!
I was so confused - I thought this thread was about EM6000 - Target Coatings waterborne finish.

Looking at E-6000, it looks to be an industrial strength contact cement.
Probably good for leather to wood like you said.

It is washer and dryer safe!! So ... it's got that going for it, which is nice.