I have a 7D and a 5DM2, and I now only use microadjustment for diagnostic purposes. When I get a new lens, I make sure that the sharpest AF point is with an adjustment of zero. If it requires microadjustment, I either return the lens or send it for warranty repair. I was also able to figure out that the autofocus on my 7D was defective, because microadjustment resulted in wild variations in accuracy (sometimes it was +5, sometimes -15, same lens, same distance). Needless to say, I had my 7D repaired under warranty.
Without microadjustment, it is harder to tell whether the lens is a tiny bit softer than it should be -- although comparing shots with contrast-based autofocus (i.e. live-view) with shots done with phase autofocus can provide a lot of the same information. The amazingly sharp focus I got with my 7D using contrast based autofocus was how I knew that the phase autofocus on my 7D was defective, and that it wasn't a problem with the lens.
So to the various people posting that microadjustment isn't really necessary, thank you for bringing up that question. It is still a function I want to have, but I'm not really sure it is a function I need to have (particularly if I'm careful to inspect and return any new lens that shows focus errors).
