Way to not get it. The talents are not done, so all those forums you are talking about are working on incorrect and incomplete data. Further, GC even says that there might be builds that are better for a specific given fight. But overall there should not be an "always best" build. In fact, the system as they have proposed it means that for all but the bleeding edge progression guilds, spec will matter far less than it does now when talking about your overall performance. So you could go against what is commonly accepted as the "best" build for that fight and not lose so much that you are dragging the rest of the raid down.