I can tell you there are 19whp between CES and the Brute on a 265 kit. I would approximate Paul's header with CES for the most part (though Pauls welding work is peerless).
There is a new exhaust in development for high HP bikes, it stands a good chance of at least matching the Brute, chances are I'll be the first with it fitted to a Carp bike. Plan is to baseline the CES at the local shop to find the delta between the local dyno and bob's, then get the new exhaust tested. Trying to be complete with this by early April.