I use them sometimes if she has time off working in a frame for whatever reason, I mostly used them when I began working her in a frame, because she didnt get the idea at all. Now I only use them when practicing working in a snaffle. Brooke is reaaallly strong so I use them first, to get her used to being round iin snaffle. Helps with the transition.. :)
But I find with too much use it can lead to over bending.. so I only use them occasionally.