I cannot possibly recommend localbitcoins.com highly enough. Concerning the two weeks, enforcement has been off and the network was having hiccups, so recently I'm sure there has been more variance. BUT, I have a feeling the enforcement switch is getting hit momentarily, and when enforcement is active every MN is paid evenly and consistently, like clockwork. It's completely consistent, when enforcement is ON!
The network is not having hiccups. When we do, its called a fork. What is happening is miners and pools who reverted back to non-paying protocol taking advantage of enforcement being off.
I have one MN that got payed 4 times in 5 days, and another that got nothing for over a week. Its not really random as in the old variance model, its miners not paying the MN fee.