The biggest advantage to PW hubs is the bearings themselves. They are incredibly well sealed against the elements and will last a long time even after being ridden in the harshest of environments.

One thing to keep in mind is that PW produces several different levels of bearing; the ones with the best seals (equal or greater to those found on submersible pumps) are only made for PW products, with the exception of ones made for outboard bearing BBs.

As for seal drag, they break-in very nicely after a few km and roll very well.

All that being said I'm very happy with the PW bearings in my Formula hubs.