I was a sceptic initially but love it now.
I tend to start looking at it as I start my first rough mix (often I'll do all kinds of things after then, so it's a fairly early stage). It's the usual thing - I get used to how something sounds when I'm endlessly pouring over it, and I need a bit of perspective. I prefer having something visual to reference mixes - just my choice. It nearly always proves to be helpful.