Superlap bottom bracket
 

So I have used the sugino 75 bottom bracket... but whats the superlap? Is it really a better bottom bracket? Will it last longer? Is it just some obserdity like the grand mighty with some couple dozen or more passes through forging. Just curious thats all.

Yes, on Super Lap the bearing cups are just smoother and better finished on the inside but it will make absolutely no difference (except the price...) if/when you're riding on the street.

Yeah I guess the superlaps bearing races are high polished.
I cant imagine anyone anywhere in any situation would notice any difference. Track or Street.

I wonder how one could scientifically test or compare the polished and unpolished bottom brackets against each other?

I visited a site the other night in which the maker of hubs with super-duper bearings stated a specific reduction in the watts required for a given distance.

In the above case, the maker made an argument for the superior uniformity and roundness of the ball bearings.

difference is nominal

What do polished races matter if you're using bearing cages anyways?