1 big site vs 5 smal ones

I'm planning to build some web tutorials site/s but I don't know if I should go with 5 micro niche sites or 1 big one? Which ones will be easier to rank?

Google is putting more value in authority sites. So in the long run, one big site will probably pay off.
That being said I have about 100 small sites that all rank well, and will be linking to my main site and giving it a good push.