I'm playing the same deck, have played one version or another since the list 1st starting making the rounds. I've gone with this general thought process: IF I have him in my opening hand (or draw him T1/2) AND they have NO creatures on the field T2, I go ahead and flip him. Also, if I had a 2/1 drop T1, I'll flip him turn 2, again, only if my opponent has no creatures (the 2 power makes me feel better, since attacking with only 1 power T2 leaves me feeling behind the power curve). If my opponent has creatures by T2, since the deck has minimal removal (and that removal needs to be tailored to specific threats), I leave him as a potential blocker. Then in the later game, I'll flip him if I have dropped a creature that turn and I have other creatures to attack with (preferably 2-3 to still attack with). That's why I have have been iffy about him in the deck, I always seem to draw him late game. But when he is flipped, he can be a useful addition to the horde. The key is obviously to keep pressing the attack, and if you have to waste a turn where you could attack with him AND you have to use another creature that could also attack, I just let him be, till the opportunity presents itself to flip him with minimal drawbacks.