I think he (kim) meant that Instosis win rate was only 30% until he played enough matches. My Instosis winrate is 54,65% after 2002 matches, so I can say yours (rob) is correct.
With PoisonDial I'm at 60,09% after 212 matches so far, I don't think I can go much higher. In the long run it seems you lose very often against medium FG that in the OP have a very good score (one above all is Dream Catcher, 6-1 is something I don't understand, it almost always play an early Discord and I usually have only 1 tower and there is quicksand also) and you can even lose against easy deck with a bad hand (once I got 1 sundial and 0 SoSac and I've been rushed to death by Akebono). While with Instosis I had some FG I was getting better results than the OP and some that I was getting worse results, with PoisonDial they're pretty much all a little (and some a lot) worse.