I ran the TRP CX9 mini-v for a few seasons of cross back in my rim brake days. They provided more power, but you have to run the pads super close to the rims so mud/wet grass/etc got jammed up in them really easily.
The modulation kind of sucked - the levers feel really mushy.

I eventually switched back to standard cantilevers (Avid Shorty Ultimate) and found that with the right setup and good pads, they worked better - though they do require a little more hand strength on the levers.

I don't have any good photos of my setup, but if you google "TRP CX9" you'll find loads of them.