I haven't used a guide. I have been fortunate enough to know a few good guides and most of them have shared knowledge with me. Also, I am a steelheader and know many other steelheaders. If I am traveling to a river system I don't know usually one of my friends does. Another thing, most steelhead will hold in the same kind of water no matter what river system they are in so once you learn where to find them the skill can be applied to almost any steelhead river.
If I were going to fish somewhere exotic like the Bahamas or such for a species I had no idea how to fish for then I would likely hire a guide.
"The reason you have a good vision is you're standing on the shoulders of giants." ~ Andy Batcho