There's no audible distortion unless I crank it 3dB above reference level. By that time it is unbearably loud!

Some material sounds unnatural with DPLII no matter how I tweak the settings. Neo sounds natural. I favor 2-channel for all well-recorded pieces. In my space, well-recorded 2-channel shines with the M80s and EP600.

I'd hate to break it to you but you won't achieve what I have in any of your spaces. The best you'll be able to do is to put speakers on your long wall.