The M5s are rear-ported so you need to account for that unless you get wall-mounts. According to my ears, M5s will give you noticeably better performance than M3s and QS8s throughout the entire range.
There's not a wall behind where they'll be. I just didn't want to push them any further into the rest of the space. It's an open layout, but I want shelving for books separating the HT space from the dining/project area, and the rear surrounds would either be mounted to the shelving itself or resting on it.
