Assuming deep stacks, You should be more likely to check because your draw is to the "Nuts".
Reason 1 --- If you hit your draw, you could win money from someone who would have folded to your semibluff.
Reason 2 --- If last to act, you can take off a free card to hit your draw and stack your opponent. A check raise may force you to fold your "Nut" draw
With a draw not to the "Nuts", your more interested in winning the pot right there if nobody flopped much. ex: As7s 2s Js Jh.
With the "Nut" draw, you have hopes of stacking someone ex: As7s 2s 5s Jh
Note, I am not saying you should never semibluff the "Nut" flush draw. Just be more inclined to check...LizaBuv