Actually, the old Blood Gulch lightmaps were more accurate for a scene in broad daylight. Shadows shouldn't be that defined when you have an immensely bright light source having its rays scattered and diffused in every direction.

So, yeah, MR is faster, but why is it faster? I doubt it's some magic code overcoming the fact that Maya has a ton more resource overhead than Tool. More likely it's just not doing as much. Which is fine, because options are always nice to have.