Free form roleplaying requires a consent heavy environment and a group where there is a ton of trust. Along with that, it requires either enough canonical information or enough leeway that players have a framework to work in, or can make their own framework.

The more freeform something is the more you need to rely on trusting other players in order to get anything done.

On the flipside, however, the more coded something is, I think there's a mentality (at least in my experience) where it comes down to, "Well, there's nothing that says I can't kill you, so too bad." And it's hindered my ability to enjoy the community of more heavily coded games.

I'm personally a fan of the peripherary coded systems, where the use is optional (and to one's benefit when used), but if you don't use most of them it's not like you're going to have issues playing.