Eric, for that sized room, I don't think your going to notice that much difference between the two, especially at lower volumes. Even at high volumes in that place, either model will bring a smile to your face. Yes here is a bit of a difference between the 60's and 80's, which would be expected with an extra tweeter/midrange.
I will tell you that my room is 9 times bigger than yours, and I owned 60's for about 3 years before I upgraded to the 80's. The 60's have great detail, in my opinion, and are killer for HT and movies as well as cranked up tunes.