Don't you think it's better if there are several persons asssigned to review one's account when they reached the number of activity required?
It's up them whether a certain account would rank up.
I think that many people won't get much attention in their posts. If your post isn't visible enough, though the quality is there, you won't still get a merit.
For sure, many repititive post will be seen since everybody wants to get an attention.
But overall, the idea of the merit system is great.