I used FLP on Saturday when I went. I did get some looks every once in a while and was able to hit 20 rides. I could have had many many more if I wanted but thought it would be entirely disrespectful to marathon "Orion" on a day like that. I wanted to badly but decided against doing something like that on a VERY busy day.
I usually go to Kings Island during the week and never buy FLP or FL because it's never needed. However, I almost always buy FLP if I go on a weekend. It certainly has it's pro's and con's. Overall I think it's balances out most of the time as the park isn't as busy as Saturday even 90% of it's operating season.