I dislike them, I didn't like them even before interchangeable choke tubes hit the market. In addition to the appearance of the thing on the end of a barrel, if you are making choke changes in the field, unless you unload your gun first, it is dangerous to be fiddling around with the muzzle of loaded firearm. Additionally, you never know if you are going to have a close shot or a far shot when game flushes out. Better to have two barrels with two different chokes, then you are ready for most circumstances.
When you are up to your butt in alligators, it is hard to remember your intent was to drain the swamp. Stay focused!