For the record, I was the only other miner in icemining Sumo pool for quite a while and I had no problems at all with the way the pool was running. I feel I made excellent amounts of Sumo while I was there.
Reason I left is because I had a major issue with my mining rig and when I finally got it fixed I decided to mine a different coin for a while.
I was actually quite disappointed when I came back to mine Sumo again and I saw that the pool is offline.
Also, I had a short e-mail exchange with the pool operator and he seemed to me to be a nice, helpful person.
Just my 2 cents.