They've been around at least as long as mortise and tenon joints, tapered or straight. It is SO easy to construct, assemble and disassemble. I think the drawing is self explanatory. Drill the holes for the bolt oversize so the system will accomodate misalignments. The only warning which is appropriate relates to tightening the bolt.
Finger tight is quite sufficient.
So if you do a vector diagram of the forces acting on the joint, you'll find that most of the stress is compression of the neck INTO the guitar, and only a minor portion is tension actually acting on the bolt and the wood surrounding the dowel. So it appears to be far stronger than it needs to be.