Only just started playing with docker and I'm surprised at how long it takes to start a container up and the size some of them end up being.
If I had more time I'd probably build multiple VMs and use snapshots.
There only appear to be two advantages:
1. that it's simple to use someone else's base docker and add to it quickly. But that advantage disappears if you rarely make a subsequent change to what you are using.
2. Your containers contents are well defined in a docker file.