I've never heard of them before? Anyone like or dislike them? What kind of action do they have?

Thanks

Have you googled it? It is a bit with LOTS of gag. The bit will never hit the end to provide firm pressure, it is gag the whole way.

If you are interested in trying one before you buy, here is a cool new website that has bit rentals.

https://www.baroabit.com/