Dave, I've owned 60's and currently the 80's. My room is even bigger than yours. My 5-6yr old Denon 2805 played both in my room to levels most people don't listen. In my mind, most people will be hard pressed to tell much difference. The 80's give you a little more detail because of the dual tweets and mids, but not a huge difference. I also found them similar in the bass category.
Honestly, I never thought it could sound any better than my old m60's, I had them for a couple of years. Yes, the 80's peer preassure got to me, and I melted and gave in to 80's.. I do love my 80's, but kinda miss my 60's. ;(
