Thanks guys.
I agree with Jim (Gunzorro) that the 17-40L isn't in the same league as the 16-35/2.8L II. I owned one for about seven years. I have posted extensive IQ comparisons between the 17-40L and a variety of Alts, mostly on the Alt forum.
I'm like Ben, in that I usually only take the TS-E 17/4L when I know that I want to use tilt or (most often) shift. That's why I bought the 18 ZE, for when I'm not carrying the TS-E 17/4L. One of my common setups when traveling to a 'photo' destination, especially when I'm shooting events there, is the three f/2.8 II zooms (16-35, 24-70, and 70-200 IS II), two bodies (either 1DX + 1DIV or two 6D), and 18ZE, 24/2.8 IS, 40/2.8, 85/1.8, and 135/2.