More often than not, they don't work well, or they alter sound too much. A well set up parametric EQ works much better to help eliminate feedback potential and problems. Overhead mics lock you into one location, but they're always there for you. Stand mics are more flexible, and the overall quality is better, the selection is better. But, with stand mics, you have stands, which can get in the way and crowd up the stage too much.
Patch bays are wonderful but do require some maintenance over time.
You can do a lot more with a patch bay, but for just changing mic channels, I like the snake box.