That's been my experience with hubs of all sorts, not just road hubs.

I've had Alivio MTB hubs and up to XT hubs. In road stuff I've got a no name and up to an old Ultegra I got used. Now all these are cup and cone deals and when set up with a fine touch on the preload they all spin really nicely. The only other place I've noticed a difference is the freehub pawls. When you jump to some point in the lineups the freehubs seem to run a little more smoothly. It may be just my samples or it could be that the upper end freehubs are made differently other than just the seals as mentioned.

For this reason I've always gone with good solid mid to mid-upper components where you get a really nice bang for the buck and they are finished to a nice degree without that last bit of attention that can add significantly to the cost.

But having said that it's nice to have the better looking parts with the nicer outer machining and finish. It shames us into riding fast/well enough to do justice to the parts we have...