Liquid Antimatter with CP plays pretty well vs. Platinum. I don't have many of the cards upgraded but it still wins enough to make plenty of
All I have upgraded is 1 LS, 6 CP, and 2 vamp daggers and I win 1 out of 4 or so which makes money. All upped I think it could do even better. Right now many platinum decks are heavy control with some big hitters. Liquid Antimatter works well against that.
Gold seems to be where it is at now though. The reward there is getting pretty close to platinum.