I grew up with butter out, but now we use the fake stuff for toast and I think it works great. My wife even cooks with it, so we hardly have butter around.

However, we visited my wife's grandmother over Thanksgiving and she keeps the butter out. What I didn't realize, however, is that every time the "mound" of butter she keeps out gets low, she piles more on. That means the bottom butter is, well. . . old. I was grateful that she had just put more on before we ate because at least what I was getting was fresh. It was at that point my wife informed me that her grandmother "shapes" the butter with her bare hands and doesn't wash them first. . . and she did this after cooking with raw chicken. At least I didn't get sick, but I'll be very careful what I eat next time we go.