Depending on how tall your speakers are, I'd go with wall with the sloping ceiling. You should also consider where you're going to place your equipment rack/stand. If you look at the virtual systems section, you see that over 95% of them have equipment between the speakers. IMO, you want to keep source equipment away from the speakers, and big racks and video screens do not enhanse imaging.
Having your main front speakers 5' off the wall will be great for imaging, but you'll also have some peaks and dips
in bass response to deal with.
Having your main front speakers 5' off the wall will be great for imaging, but you'll also have some peaks and dips
in bass response to deal with.