JaimeG,
Yes, the room does make a substantial difference indeed. I noted my thoughts after hearing my setup over at a friend's house.

You might be able to increase the bass a bit by moving your M60s closer to a wall. Otherwise, if you do not already have one, i suggest you pick up a subwoofer to help fill in some of that low end in the larger room.

"Those who preach the myths of audio are ignorant of truth."