I know what you mean about all the rafts in Brown's Canyon and how they can run you down. I've bounced off a few rafts in my kayak and been under a raft twice.
But, I'm not that negative on the raft guides. They don't really have the meaneverability to avoid you, especially with a paddle raft. At low flows, their line is pretty precise. And, the boat upstream does have right of way.
I would just as soon have it that way too. In a kayak or IK, I'm more meaneverable than they are. If one of us has to move, I'd rather it be me. And since they have right of way, it kind of should be me who moves. Sometimes I cut it a bit close, and I pay the consequences......
Yea, the traffic there can be bad. But, if you launch late in the afternoon, the canyon is all yours.
Also, most of the guides are pretty cool and professional.