Hi,
I run https://www.megamineros.com/CSC and its a small pool. In the long run it does not matter that much if you mine on a big or a small pool. Short term a small pool can be more erratic but on longer time spans like a week or more there is no or little difference. The last two weeks did have large fluctuations and there are higher spikes in finding blocks, that is all caused by the coinhoppers. They really impact difficulty and are damaging the stability of coins. Also this complicates the calculations on which the predictions are based.

What can be a danger is having one pool getting too big and getting more than 50% of the network hashrate. That can really endanger a coin and miners should spread out over the various pools and not all stick to the same. Mining is not only about finding coins but also in handling transactions, ... if the network goes down the coin dies with it! In cgminer you can load balance your mining power over various mining pools and thus helping the network stability and its future.