I own it and love it, and it gets plenty of use in a household that also has a 70-200/2.8 IS (old version though), 70-200/4 IS, 70-300 L, and 100-400 II. Honestly, it comes down to weight for me: I've had the 70-200/2.8 IS since December 2007, and it was a great workhorse even though it's a little soft at the long end wide-open. Then my wife got the 70-200/4 IS, and I realized that I'd often "steal" hers if I didn't need f/2.8. I then realized that most of the time that I don't need f/2.8, I also don't need IS, so that made the decision to get the non-IS a lot easier.

I was using it for headshots, as I follow Peter Hurley and it's the lens that he uses daily on a 5DsR. I've recently switched to the 100 Macro because I realized that my hand/eye coordination wasn't where it needed to be for zooming, and the 100 prime gives me a lot more consistency. I do suspect that I'll go back to the 70-200/4 in a few months to get just a touch wider (Peter can set his to 91mm without looking, and that's usually where he shoots headshots). I still use it for lots of other things though, and it probably competes with the 70-300L more than anything else in our fleet.