they un-bind considerably after even just a little bit of use, but they'll never be quite as free-spinning as clean, well adjusted loose balls. The benefit is, they tend to require less attention, and you don't need to worry about cups becoming pitted, which will ultimately be the death of a loose-ball hub. (Granted, this will take many years/miles with proper maintenance.) I've come to really and truly love sealed bearings in headsets (although most of my bikes have tange loose-ball w/cages threaded headsets), because the headsets don't rotate continuously, and any little bit of drag is not even a concern. I find that the drag in a BB caused by sealed bearings is no real big deal, but after trying both sealed and loose hubs, i still have a soft-spot for Shimano hubs. They're so tunable, so easy (if a bit sloppy) to maintain, and so cool insofar as they're a very modern interpretation of what is essentially a dead piece of tech in everyone else's hubs. (Still, quality hubs with sealed bearings spin like crazy when properly adjusted, and in many cases, adjustment isn't even an issue! This last point can be seen as a pro or con, depending on your philosophy.)

-rob