In the old days with cup & cone bearings, I'm all over the concept of regular service. But with cartridge bearings, I'm not really sure what I'm doing taking the hub apart to just look at the little cartridge. Wheels are running smoothly and there's no play. Is there a point to opening them up?
I'm pretty sure I have cartridges on most/all my bikes. Shimano XT hubs on MTB and commuter, and I have Velomax Circuit Comp and Mavic Aksium on road bikes.
Seeing as I've screwed up a couple of non-bike things of late by trying to improve on adequacy, I'm in a risk averse mood lately. But for some reason I've got a burning desire to tear into these things.