So I ended up with the port-aft cabin. Tried not running the AC - and at least on this boat (45' Lagoon) it wasn't an option. You get very little air flow (and with rain almost every night, it just doesn't work.). I think the aft cabin may be a bit quieter than the forward cabins as the mooring ball constantly slaps at the hull - and since that is happening up front, my guess is that it's louder up there. All-in-all there didn't seem to be much difference between fore and aft.