There have been some pilot projects with reduced speed zones in place for a couple of years now in certain neighbourhoods, but I don't think I've seen any data on the outcomes. I guess it tracks that they must be satisfied with them, for them to want to make the change citywide.
I haven't encountered too many of the "clutter" zones, but when I have, they have certainly done their jobs.
That's pretty permissive overall - I like it.