Just my opinion but I can’t stand my one eared bridles!! Some horses have ears that are too fat, they end up in the wrong place, they just annoy me… they are often pretty but I just think browband’s are much easier and frankly nicer to the horse, I’m always apologizing while stuffing their ear through or accidentally bending it.
With either style I always look for a throat latch, For showing I can do without but that happens almost never As for snaffle / leverage type bits I’ve never heard of that, IME I’ve never had an issue with either combination but I guess if I ever show western again I’ll know something new!