Interesting test indeed. What i see on zpool a lot is that it takes ages for some coin to mature according to the view.
I stopped mining to my BTC-address because of the fees a while ago and there are still some coins shown as immature for scrypt and x11.
A lot of other stuff like birthmark seems to take ages until it is ready for cash-out.
I had the same problem with my L3's. I still after almost 12 days have coins stuck in maturing. That, the fact that they do not pay remotely as advertised and my loss of HR all turned me against using zpool in the future again.
I believe there are few people who actually make more money on zpool, but I have never been able to even beat litecoinpool.org and that is a lot lower than multi-pools already