I dunno if I like check shipping here that much tbh. The fish vill clearly also has some 6x in his range. Also if you check the range of hands that are betting is pretty narrow imo. I'd expect to see most mid pairs, FDs and even some weak Qx checked behind on this dry of a board. It's kind of a meh spot since betting folds out basically all the FDs that remain and narrows your value range to Qx and middling pairs that don't believe you have them beat because (LOL BOARD PAIRED!)

That said, I think betting like 5 is going to be fine here since CO may call with some of his middle stuff, and SB is never folding Q9+. SB might also find a call with some raggedy spades. I mean if CO folds then who cares, you still most likely get to play a biggish pot IP vs a fish with an OP.