LOVE the site, lack (became premium within hours of discovering it!)
However...
I think it would be REALLY useful to have a full explanation of the team mechanics laid out in the "How To Play" section. I referred a friend today who joined a Triples game and accidentally deployed his armies onto a teammates country without even realizing this COULD be done. He was VERY frustrated with the site as this was his first game.
Luckily, I think I talked him into hanging around, but a simple "How To Play Teams" section would alleviate the problem in the future.
-Aahz