I have shot all of these and owned two. They are all fine pistols. The only difference between them - and it's the most important difference - is which one you personally like best. All three of these have radically different grip sizes, grip angles, and trigger feel. The 1911 will have the slimmest grip. The CZ is rather chunky with a fairly long trigger reach and you may not like it if you have small to medium size hands. If you have very large hands, you might think it was custom made for you. The SIG is somewhere in between.
Short answer: you need to handle all three, dry fire if you can, rent or borrow if at all possible, before you make your decision.
Short answer: you need to handle all three, dry fire if you can, rent or borrow if at all possible, before you make your decision.