There is no performance advantage to a "good" hub. Bearing friction is not a significant source of drag. Its all about bling really. Even if trashy hubs come with bad bearings (which they don't usually), its cheap to replace them with good bearings. What other aspects to a hub are there? Hubs almost never break, not even the cheap ones. As long as the axle spins, the flanges don't brake, and the threads don't strip, its doing its job.