It seems like esea is opposed philosophically, however it is probably the better product. Automatic win recording makes what happen to London impossible. I mean yeah there's a ton to be desired, but esea finally added med stats and med picks.
Cevo is probably more approachable as the admins are a lot more friendly and talkable to. You see them in stream chats, and on forums far more often than killing or tri. But esea has had more than 4 years experience running a 6v6 league so there are less issues but when they do happen more intensely, probably due to the automation.
The choice is either the experienced league that has a slightly better product, or the new league with approachable admins.