Had a bit of a debate with friends earlier, they think I should be putting in 2 hours of study a day at micros.. I think this is excessive and you should focus on just beating  them at say 6bb/100 then move up as soon as possible. They said that any study will help improve your game at higher stakes so is worth doing. 

They also backed the idea that you once you get to 400nl you should have a 50/50 study/play ratio. Thoughts?