I always use smart routing on Interactive Broker. My default is set to the midpoint between the bid and ask. Usually I send my orders as limit orders at the midpoint. I absolutely HATE trying to save 5 or 10 cents and watching the market slip away from me, then paying 40 cents more. So I take the midpoint and call it a day.
Are you guys saying smart routing on IB isn’t all the smart, and I should be manually trying the different venues? And is coming in at the midpoint particularly weak?
To answer your immediate question: I am not familiar enough -- when I have shopped, I have paid more, but the sample size is quite small -- once a quarter for 5-6 years? So, I saw no reason to change, but based on loose data.
Back to your OP, you'll find a better market on 'fence post' strikes -- the ones that are there from the earliest promulgation of the expiry -- big, round numbers, in 10s and 50s, for example.
(For small example, if you wanted to short the SPX at around 2400, you'd have a harder market than 2395 or 2405. Same with a spread, too -- trying to sell of an "orphan strike" long is a pain, a time-waster, and a dollar-eater.) If you can plan your exits to not be on orphan strikes, but on big ol' fencepost strikes, you'll be a happier camper.