Just to add to the info above, yes, Disney does offer some room-only discounts to AP holders. They generally follow the same pattern as Disney's other seasonal discounts in that the availability of a discount to any given resort/room type/view category can be limited. Meaning, not every available room will automatically have an AP discount available to it. Disney's standard "The number of rooms allocated for this offer is limited" disclaimer is in full effect with AP discounts.
The AP discount is often a bit better than the general public discount that's out at any given point in time (eg, 5-10% better), but that's not always the case.
The AP discounts usually come out after general public and other discounts, but AP holders have a longer window to book - meaning the "book by" date is longer.
There's more to it than that but that's a general summary.
I can't speak to DVC.