If you're not aware, jefroman, the Chinook has a strong enough lock to be included in the Spdyerco Martial Blade Craft (MBC) rating system. The Gunting also qualifies, and maybe the Military -- not sure. Anyhow, point is, the Chinook's lockback is way stouter than most. I don't believe Spyderco has tested competitors knives. If they have, they're not publishing the results. I think it unlikely that you'll find any other lockback to be as strong as the Chinook.
It is realistic to expect that the Axis and Rolling locks would meet the standard. Some frame locks undoubtedly would qualify also. I think you could trust the toughness of both the BM 705/710 and the new 550 (I think) Griptilian. The Griptilian is in a lower price range than the others mentioned. From all I've read, it provides a big bang for the buck. Many people think the 710 will go down in knife history as one of the benchmarks of folders. (Maybe thats high water marks)
Since you seem at least moderately interested in Spydercos, I think you might want to consider the Wegner, tho it is a liner lock. It isn't strong enough to pass the MBC standard, though I believe it is listed as heavy duty. It has a wonderful feature -- the ricasso, the bottom part of the knife from the end of the sharpened edge back to the back end of the blade tang is flat, and the full thickness of the blade. Since the Wegner has an unusually thick blade, this means that if the lock should ever fail, it is that ricasso that will come in contact with your finger(s). None would be cut or amputated. Gives me a lot of confidence in my Wegner.
Good luck in your choosing.