Love the webmasters - and I still use them, but I think true escape artists need extra care if they're cunning enough. My guys have had several escapes, even with the harnesses.
First, the webbing that holds the metal lead clasp to the harness wore through after 6 months. This was spooky because there was no sign the webbing was wearing. The harness was taken to a clothing place who put a new, reinforced strap on.
Six months later that wore though - again, despite daily inspection, there was no sign of fraying etc. The harness was then taken to a saddlery with instructions to make it bulletproof.
A month after that - The alleged high-quality lead (bought after the cheaper lead broke) went 'pop' and let one dog escape. Turns out it's possible to twist the clasp of most leads a certain way and have them pop loose.
My solution was a trip to Bunnings that resulted in a home-made lead (1t working load rope, spliced at both ends), attached to the harness via a 1t quicklink (intended for joining chains), then a 200kg rope from that going to the collar. I figure if they manage to escape from that, they deserve their freedom.
The harnesses are great (no chance of slipping backwards imo) but the attachment to the leash is a weak point. Admittedly this is what a relaxed walk looks like.