In my main band it's a sort of mix (but mostly democratic) and it works. I've been working with the singer/guitarist for 6 years now, and I've rarely gotten genuinely frustrated about how things go.
The singer/guitarist and I are pretty much co-founders, yet we do follow mostly his vision. We started working together in a different band, which was his band, and when that fell apart I decided to stick with him, and thus we both started our current band together.
So, we do follow his original vision, but I have a lot of say/sway, and the other guys (second guitarist and drummer) always have a say in details, specifics, desires, and likes and dislikes about what we do. It pretty much always comes down to a vote on everything.
Anyone can say anything, and it will always be taken into account or discussed, because we've been lucky enough to become a band where everyone wants us to be the best we can be. So we can all trust in each other's intentions. It's just that we have a main goal, and sound, that the s/g and I try not to lose sight of. So we both guide things, together or seperate, and usually start the conversations about goals, or other things that need to happen. But anyone can start a discussion about anything and we'll all listen.
So. Yeah. I like the way we work. It can be a bit tense, but because we're all very open it never becomes a lasting issue.
We all keep each other in check pretty much x) .