I've been using it since the @last days and it's still King for conceptual stuff but I have recognized like others that I need to move to Revit soon. That's just what the Arch world uses.
The other thing holding SU back is the lack of tools to deploy it in larger companies. No corporate license key for multiple installs unless you are a network license holder, plugin deployment is a nightmare and setting a common default toolbar arrangement beyond 'getting started' just isn't possible. It also frustrates me that many of the popular free plugins that we all seem to rely on have still not made it into Pro. Trimble could easily pay for the IP or license it. Having to side-load 2 dozen plugins to make it usable for us is unsustainable.