My experience is that I'm somewhere between the two camps -- I had to replace my hubs for the first time at 46,000 miles.  I knew at least one of the original hubs was going bad when this grinding sound would get louder and louder the faster the car went.  I was also familiar with the sound from my last car whose hubs had also gone bad.  With my previous car, I replaced one problem front hub before the other front started to go bad three months later, then both rears a few months after that.  This time, I went with all four new hubs.  Besides, all four wheels went the same distance, so if one hub went bad, the others may not be far behind.

When that happened, I did my research to see what folks were using and what their experiences were.  Some folks went with ACDelco OEM parts, some went with the cheapest hubs they could.  Two brands were frequently cited as excellent hub manufacturers -- Timken and SKF.  

I went with the SKF units.  They fit well, the replacement work went smoothly, and the reviews I found were overwhelmingly positive.  

The installation on these hubs went very smoothly for me.  However, with my last car, the removal of the old hub was by far and away the most challenging and time-consuming part of the project.  One hub took me -- literally -- hours with a slide hammer to get the old unit to come off.  Eventually, the housing of the hub broke before the the rest of the unit would separate from the axle.

For what it's worth, the OEM units from ACDelco cost quite a bit more than the SKF and Timken units.  I saved about $212 on all four hubs by going with the aftermarket units as opposed to the OEM ACDelco units.

* note: the links are for single hubs; if you want to replace both of an axle's hubs, you'll need two hubs