I've experienced both sides - went through Rush as a freshman in 1992, when it was still rush and still had frills. By the time I graduated, the frills were starting to disappear and things were transitioning to "recruitment" vs "rush."
When I rushed, we all sang the guests in and out of the house. (Though we couldn't cross the threshold of the doorway - I think they stopped letting them go out into the yard at my school in the late 80s.) It drove the neighbors nuts, but I guess they should have known what they were getting into renting a house next to or across from a sorority house.
Besides, it was only once a year in the Fall.
My sophomore year, we had an awesome rainforest theme for Phase B. It was quite stunning and impressive - we had a small waterfall in the corner, live trees, a canopy of vines/greenery over our formal room...I'll have to dig out pictures, because the description doesn't even begin to do it justice. I don't even want to think about how much that level of elaborate decoration cost though.
I'll also agree with the last paragraph of carnation's post.