Thanks for the feedback all. I'd normally b/f flop and turn but have been trying out some weird lines against some of the nitty 10nl regs on Stars lately with some success (whilst it's cheap - admittedly, this is not one that went well or worked). There's a lot of players at 10nl on Stars however that can't lay down a medium overpair on 2/3 streets to a bluff and flat call all the way, which has cost me a fair bit lately.

Just to get back to my original thinking: if I was in position and facing a c-bet on this flop, would you be more likely to float with a backdoor flush draw with the 15 or 18 cards that I mentioned originally?