I worked for Echo my first season as a guide - it was a generally good experience. I trained at a company in Vail that only hired 6 out of 27 people in their training class after promising to hire 60-70%
. On the other hand Echo took 13 people for training and hired 12 - I got the final spot. Echo generally treated me well.
The one thing to look out for there was they required people to be on stand-by 6 days a week, if you wanted to only be on standby 5 days a week you lost at least one half day trip if not a full days work in the rotation. Out of 6 days I usually worked 4 to 4 and 1/2 days out of 6. I know that Echo is under new ownership since I worked there so this and other things may have changed. I think Ben is still the head guy there (was there last season) and he is a good guy.
I don't know much about Raft Masters other than we used to call them bad names - like Ass Blasters. But the guides I knew from there were good people. Echo is on top of a mesa about ten miles out of Canon City, Raft Masters is in town - pros and cons to both set-ups. Echo offers camping for their guides on-site, but it gets hot and there isn't much shade up there. When I worked there there weren't flush toilets, showers, or a guide lounge - I don't know if Raft Masters offers camping for their guides or any other amenities. Some outfitters have guide lounges with internet access, tv, showers and other amenities that are really nice. PM me if you have more questions.