I have my M80's about 9 inches from the back wall and about 60 inches from each other and they just sound great.

I could have done fine with M60s and even M22s for my lsitening area of abut 2000 sq feet.

But I know I would have second guessed myself all the time. If you can afford them go with M80s. They sound great and the clarity and musicality at low volumes is amazing.

also they are very sturdy on my hardwood floors, so would be safe from toppling over.