I reckon the bearings in the Shimano hubs are far superior to the BHS hubs. Cartridge bearings only seem to spin smooth for a % of their lifetime, cup and cone bearings seem to spin smooth for their whole lifetime.
The flange spacings are also much better to allow for the low spoke count. Stiffness/Strength is not just a function of spoke count. I'd much rather use the Shimano hubs than the BHS hubs, nothing against the BHS hubs though, great weight for the money. If you're trying to get the lightest wheel for the money, BHS hubs on 20mm tubular rims all the way, but if weight isn't a concern, I see nothing wrong with the shimano hubs and some slightly deeper/stiffer rims
I write the weightweenies blog, hope you like it My SwiftCarbon UltravoxMy Velocite Selene
Disclosure: I'm sponsored by Velocite, but I do give my honest opinion about them (I'm endorsed to race their bikes, not say nice things about them)