Great thread. I think the physiology of the bridge is also important, at least astetically speaking.
Some players use a closed bridge whereby the index finger is placed on top of the middle finger. To me this style is the best looking of all the bridge types. The downside with this particular bridge, at least for me however, is that my fingers are so short and stubby that I am unable to form the bridge and am forced to use one that is more Mosconi like where the index finger curls around the cue shaft.
A good bridge is certainly important. Just ask my Uncle. He went flying off an unfinished bridge one night at about eighty miles an hour. I guess he settled the closed or open question once and for all. :wink:
That first bridge you mention may look nice, but that isn't it's principle benefit imho. Placing the first finger on the second finger forces (or rather promotes) the first knuckle of the first finger to be locked straight. This makes it so that the cue rests against the side of the knuckle. There is the least amount of flesh and skin here, thus the cue slides more easily. You can get all the pressure you want, but with very little surface area of your finger actually touching the cue. This promotes a very smooth stroke. Pretty much all the Philippinos use this type of bridge. And yeah, it does look cool!
KMRUNOUT