do you find that now that you have this solution, you would be using the 16mm end a lot less on your 16-35L?
Hell no! The 16-35L is STILL my bread and butter, baby. I still use the 16mm end a lot. The 15mm is for those times when I really need to get so much more in the frame and the 16-35L just won't cut it. Plus, it's still fishy even with the 1.3x crop, so it doubles as just a fun lens to have. Try it on for size.