I'll try to getthings started...you ask a mouth full!
650s are one of the cadillac coyote traps and if you got the bucks go for them you won't be disappointed.
Rdfx just did this one; night latching is a secondary notch filed into the pan. To set the latch you set the dog in the factory notch and then slowly push the pan down...when the dog jumps into the secondary notch you hear a click, ergo you can set them in the dark. However, with a bit more filing to square up the dog face and notch you have a gun latch which gives the audible click, consistent setting point and minimizes pan drop. Combine this feature with correct pan tension and you've got yourself a dandy setup.
I have and use bridger #2s and 3s. I find they work fine. I have most of mine fully modified. My #3s will all be base plated next year...it helps on the mean ones! I don't set a trap that isn't offset and I like 1/4 too 3/8 inch for cats and yotes. Laminating is fine and helps minimize foot damage. However, you're adding weight and drag to the jaws and will definitely need to consider four coiling. All mine are four coiled ...to help come up through lightly froozen soil. On my Bridgers some are laminated but I'm not seeing a great difference in foot damage between the two jaws types and I've had no pull outs on either jaw.
Man I have an asortment of traps! I really can't complain other than I don't care for and therefore don't set Victor #2 low lever square jaws any more. But I never lost a yote with one either. Double longs are the mark of the western trapper and there are a bunch around here cheap. Mine are all on drags and they take a bigger hole and a bunch more dry or waxed dirt to keep workin in the winter (think this fact over). Just this year I gave in and purchased some 1 3/4 victors and modified them. On short chains, at least, they held some of the the meanest ones I caught. I would never intentionally set this small of a trap for cats...superstition, maybe, but those big jaws of #3s and even #4s look real good on $200 to $300 cats! Also, those big feet have a better chance of being thrown on small jaws. One other thing, over the years I have picked up a number of the BMI traps, these, apperantly little guys have performed flawlessly for me on yotes.
Hopefully T-man will respond also he has a bunch of time in with the smaller traps and uses some of the other Brands. Hope this helps some.