I had a two day trip to Kings Island last July. The first day was Thursday, and most rides were a five minute wait (except Backlot Stunt Coaster and Flight of Fear (which I did not ride as it makes me nauseous, but my friends did.)) The next day, the park was much more crowded and my 2nd day companion and I shelled out for Fast Lane, which included The Beast. I have to admit, I loved bypassing the lines on Friday.
I have noticed that since adopting Fast Lane, lines seem much longer. However, in 2014, I must have chosen perfect days because Fast Lane was not needed except the one Friday when we bought them. I even had to wait longer to get food at The Chicken Shack than friends had to wait to ride Banshee (this ride too, makes me nauseous).
I am dismayed that The Beast has been added to Fast Lane Plus this year. It will make more money for Cedar Fair, but I would much rather be selfish and see Banshee, Flight of Fear and Firehawk on Fast Lane Plus.
Edited to correct my typos of Fast Pass, and Fast Plus Plus. Oh and Fast Pay.