Value betting river in PL

[foldingmachine]

This situation has happened a few times lately, and I'm looking for some advice if it should be played different. You flop a wap draw on a rainbow board, call a smallish bet then make your (nut) hand on turn. You pot the turn in position and get 2 or more callers. Obviouly you're praying for the board not to pair because you figure the callers for trips or a lower straight draw. River brings a blank, no low possible...but completes a backdoor flush. It's checked to you (on button)....do you value bet or check hand? In limit I have no problem betting, but since this is PL it changes the way I view it. Thoughts?

-foldingmachine