In actual play, I would c/r the flop as that is what my instinct is and I don't think enough while playing.

Investing thought, I would still c/r but am not particularly convinced it is right. I agree with those who pointed out that WA/WB doesn't apply since it is a multi-way pot. I prefer to c/r the flop rather than lead or wait for the turn since the pot is big enough that I want to thin the field somewhat. The reason for my uncertainty about what is the best line is that the 5 [img]/images/graemlins/spade.gif[/img] and 6 [img]/images/graemlins/diamond.gif[/img] are small enough that the board isn't as scary as it could be.

With your line, do you still c/r the turn if button calls?