i always have a BPS speed snap in black finish tied on my crankbait rod. idk the size, but its pretty small. when i'm using the snap, i remove the split ring off the line tie, because i've found that with the split ring and the snap it makes the bait sit nose down and sometimes even start sinking when it should suspend or something along those lines. maybe i'm just ocd about it.
but anyway, since the snap is not tight against the line tie like a knot would be, it allows your crankbaits to wobble more. i also use them on my little swimbaits i make.