FWIW, I have a relatively "new" hub on the right front and a 119,000 mile OEM hub on my left front. I did hubs up front when I did my Stoptech kit 60,000-ish miles ago, then chasing a vibration (which turned out to be tires, I'm an idiot) changed one to see if I got a bad new hub. It wasn't the hub, obviously.
The 119,000 mile hub and ~60,000 mile old hub feel the same to the hand and spin down the same, and they always have except when they were brand spankin-in new the then-new right front had a little more stiction
So, for most people, I think the E9xM hub is going to be a lifetime part or near to it. But this is still a cool upgrade because the F8x parts are such trick, machined becuz-racecar parts. I mean, just look at that rear hub! It wants to go fast:
