I don't think it truly matters. Each install will have its own concerns and priorities. In my main system, the rack is on the side due to french doors in the middle which require access and I really like the view of the doors. Due to this arrangement, or for other reasons, the system does present depth when present on the recording.
My secondary system has the cabinet and flatscreen in the middle. The speakers are closer to the frt wall as well, and depth is not as pronounced. The woofer unit is in the cabinet. This system presents a denser center fill. This system would be worse without the cabinet in the middle.
My secondary system has the cabinet and flatscreen in the middle. The speakers are closer to the frt wall as well, and depth is not as pronounced. The woofer unit is in the cabinet. This system presents a denser center fill. This system would be worse without the cabinet in the middle.