Who tried VK, will never go back to Facebook. VK is like the wild west of the web: you find everything for free, from music, to software, porn, books, etc.
Facebook is a prudish and mildly authoritarian walled garden. VK smells like freedom. ;)
Smelled, you mean. I'm not saying that all good of Vk was due to Durov, but things are obviously getting more complicated slowly since Mail.Ru group rules it. It can get even worse.