I've had this lens for a year, ever since it first came out, but I've only used it once. After a while, I forgot I had it, due to my being so used to carrying the 16-35 and 14 rectilinear. There are only so many lenses one can carry in a bag on a plane, and with the 11-24 being so large, I found myself going with what I knew, instead of what was new.
To get out of that habit, I just removed the 16-35/2.8Lii and 14/2.8Lii from my bag today, as it takes the space of both of those lenses to fit the 11-24/4L. I'm going to work the next two jobs with the 11-24 as the only WA option, in order to stop treating it as a "specialty" lens, and make more use of it's unprecedented range in UWA.
When I used it that one time before, I actually bought it as an emergency solution to my having forgotten to bring my 14 to a job where that angle was needed. I was on the opposite side of the continent, so going back home to get it wasn't an option, and there was no time to ship. I just so happened to be in a town large enough to have an independent camera store, who just so happened to have the lens in stock, due to Canon's effort to distribute at least some stock evenly around the country. Neither B&H nor Adorama had any stock, as the lens was selling like hot cakes once announced. But this little store had one. They had just received it a day before I landed. I paid full retail price, and had the tool I needed to get the job done. After I flew back home, I put it away and went back to the lenses I was used to.
In doing the shot planning for an upcoming gig, I determined that a 14mm wouldn't be wide enough , and was like... oh yeah, I've got that 11-24. So rather than bring it to use for just that one shot, I'm going to try using it for all shots under 24mm. We shall see how it goes...