Haven't really had a chance to try out the 16-35 in daylight stopped down for landscape shooting to really see how sharp it can get, but it's let me open up the night during a bit of walking around. Though I shoot a few frames on continuous 6fps, I've taken "sharp" (as sharp as ISO 1600+ can get) shots at up to 1 second at 16mm and 1/2 second at 35mm. And the 24mm f/1.4, shooting usually at f/8 for landscapes, oh my goodness is that a sharp lens! Plus the creative abilities of shooting at f/2 or f/1.4 at a wide angle to get a shallow DOF, with the nice smooth bokeh, really opens up creative opportunities in confined spaces where I couldn't use a longer lens to achieve shallow DOF. Already put a bunch of those shots in the photo-a-day threads.
Also, the 16-35mm was just in time for my trip to Iceland! I fly out the 14th and return the 24th, with the 16-35, 24, 70-200, and either the 100 or 35 and 50 (fitting everything in my one small bag to stay in carry-on with me). Also, 2x 64GB, 2x 32GB, and 2x 16GB SD cards. I'll be doing nothing but Iceland for quite a while after I get back. :)