While marginally heavier, the flange spacing on Shimano hubs has always been absolutely wonderful for balanced rear wheels. Run the trig on it, or use Damon Rinard's spocalc, and you'll see. Even without running the math, a cursory glance at the spacing compared to other hubs will show you in broad strokes how well designed the geometry has always been.

I suppose that will change with 11 speed though.

The real selling point for me is the "old-school" cup-and-cone bearings. Shimano has the largest R&D budget in the bicycle world, and has a history of pushing innovations - even unwanted ones - onto the market. And yet, they persist with these bearings. Why?

Bottom line; they simply work better, and in the hands of a good mechanic can be exceptionally well adjusted. AND, traditionally bearings perform equally well under angular-loads as they do under loads purely in-line with the bearing plane. In other words, cartridge bearings protest a little bit anytime the wheel is tipped out of a purely vertical axis. Cup-and-cone bearings don't care.

I build all my own wheels. I have White Industries hubs on one set. Shimano all around for the rest.