My experience has been that negotiations in private basically are the way to get things done in the most efficient way. It's not that public negotiations can't succeed; they can, but it's one of the complexities or anomalies of our system that cameras and the public face become an aspect of negotiation beyond the substance of the issue.
Evidence of meeting #16 for Electoral Reform in the 42nd Parliament, 1st Session. (The original version is on Parliament’s site, as are the minutes.) The winning word was issues.
A video is available from Parliament.