Really? there is such a thing as post history... you may have understood wrong but I clearly said that because Forza 5 uses a static light source, there's no reason to dynamically move environment shadows, and I specifically used an example of holding an object to a lamp, rotating the object, etc. all of the shadows cast by the object and lighting hitting the object is exactly what Forza 5 is doing, now the rest of the objects like your furniture or whatever will cast shadows as well but they won't move, so why do those need to be dynamic again? please explain why it matters unless you have day/night transitions? those shadows are baked by nature of the design.
Using the same example, what DC is doing differently is also moving the lamp, not just the object around the lamp, NOW the shadows cast by your furniture also has to shift by the nature of you moving the lamp, this adds a whole new level of calculations and sure it is technically a lot more taxing on the hardware, but from the drivers perspective and not changing the time of day, the visual effects are the same to the viewer.
There are usually large quality differences between real time and baked solutions. Baked shadows need to be relatively low resolution to keep the size of the level down. Though baked GI is usually higher quality than realtime solutions (but less accurate).