I've started grinding HBs with the deck in the general area, thread title is "How to farm Half Bloods in about 5 minutes"
Win rate feels over 50%, not sure exactly as I've been altering some cards.
Only won 2 cards so far after say... 25ish games, but the cards I won were Miracle and Arctic Squid, so thats cool. Against some HBs the deck allows you to stall pretty well to make sure your win is an EM, which is nice for the cash.
I'll have to keep track of the drop rate.
EDIT: Just played 20 games against HBs. Won 10, of which 4 were EMs, got 3 upped cards, and 2 unupped cards.