Gatorhugger is doing what many have chosen to do - stacking FMJ with JHP. I think it's a good strategy when combined with double tapping. Personally, I use all BB JHP for non cold weather carry, because I feel it has plenty of power. Gatorhugger already pointed out the key ingredient in his test - the thickness of the ham bone is much greater than what you find in a rib cage. If the BB Gold Dot does hit a heavy bone like the spine - it'll do a good job of stopping the attack, even if it goes no deeper. When I do stack for winter, it'll be BB Gold Dot and BB flat nose FMJ.
125gr does appear to be the "gold standard" for 357 magnum, although some highly experienced folks will carry the heaviest bullet they can find. For SD, however, it comes down to what makes the biggest hole at 12 inches of penetration. Heavier may go deeper, but if it isn't designed to give a bigger hole, then deeper isn't likely to be as helpful stopping the BG. It's all about what SD scenario you expect. If you are a LEO, then heavy is better because you may have to shoot through a door, windshield, or arms/legs. SD is different - close, fast, and open.
Barrel length is measured in different ways for semis vs wheels. The numbers above are the actual measured length from the tip of the bullet to the end of the barrel. It is the distance that the bullet travels under pressure that matters - that's why I choose to compare different firearms using bullet-to-end measurements. Semi-autos sure seem better when measured the other way, though! I wonder why they advertise those numbers instead of the real bullet travel measurements?