Aquineas: Depends on the udder :-). Sorry, couldn't resist.
I actually found the same thing; have a high-end PC with enough hardware to run it, but it's visually indistinguishable to me without it. Besides, I'd rather have mirror smooth without than mostly smooth with.
LOL, I really suck at typing, but yeah, I find it actually makes it look worse, makes textures look blurry. For such a demanding setting not sure what the benefit is.