Quite frankly, it has limited value in my opinion, so I don't use the feature. I believe it was provided for those who use smart phones as a way of loading the corrected coords into your phone without having use something like GSAK. If you correct the coords on the cache page (by clicking on the little pencil icon next to the coords - real intuitive), you are prompted to enter the corrected coords (such as the solved final for a puzzle, or final stage of a multi, or even someone else's more accurate coords).
The new coords replace the posted coords, but not always. If you download the GPX file for that cache from the cache page, you'll get the corrected coords for it, and only the corrected coords. But on the cache page, you'll see both the posted coords and the corrected coords on the map, with a line drawn between it. But if you view the cache on Google Maps (by clicking on the link on the left), you'll only see the corrected coords location, and not the posted coords. But if you click on the "View Larger Map" link (where it shows all the caches in that area), it shows the icon at the posted coords, not the corrected coords. Likewise, if you do a pocket query, you'll get a GPX file with the posted coords, not the corrected coords. (this has now been fixed, so pocket queries will download corrected coords). So sometimes it works the way you want, other times it doesn't.
I prefer to keep the posted coords, and update with the corrected coords in GSAK. In GSAK, you can include the posted coords as a child waypoint (or, keep the posted coords and the solved coords as a child waypoint) in case you need both, such as when the posted coords are the parking coords, or trailhead, etc. You can't do that with GC's corrected coords feature. And if you don't get the corrected coords on a query, what good is it?
As for navigating to the corrected coords in your GPS, yes, that works fine (so long as you don't override it with a pocket query). As far as your GPSr (or smart phone) is concerned, there is no difference between corrected coords and posted coords for navigation. It's as if the CO changed changed the posted coords with the solved coords. But only if you download the GPX file from the cache page, and not with a pocket query.
I continue to use the cache notes feature to keep track of the corrected coords. Cache notes are visible on the cache page, and are downloaded in the GPX files, so if you have a Garmin smart GPS (like the Oregon, Colorado, 62, etc.), you'll see the cache note in the description.
Supposedly, Groundspeak was supposed to fix this (what I consider) bug, but has not done so yet. With their track record, it's probably about as high on their priority list as bringing back Virtuals and Challenges.