If the scene contains no caustics (or even no glass/mirror), then VCM is overkill. It will do lot of heavy lifting to solve problems that are simply not there.
For examples of scenes it alone can handle have a look
http://www.smallvcm.com/ (the complicated scenes from paper).
I would look at it as method that opens new artistic opportunities, rather than speeding up the current ways of doing stuff. (At least, that was the hope when we came up with the method)
I am afraid there is no silver bullet (yet).
I got some ideas for time-adaptive algorithm, that is pretty much unpublishable, but could make production guys happy.
(Will bother Keymaster with it once his deadlines are gone).
In the meantime, I will have to re-check with him today, but I am pretty sure there is still a bug in his implementation of environment lights. These things are damn hard to catch, especially since the example implementation uses different way of envrionment light (and I am quite sure still has bugs of its own).