Knott's is a Cedar Fair park, though, and they're pretty much putting groupers in the station at all their major rides chain-wide now. Not sure what Knott's is doing right now, but in the past Ghostrider, at least, has pretty much always had a grouper. All the CF parks I've been to this year (Cedar Point, Kings Island, Valleyfair) have had groupers, even this year.
And while groupers theoretically help, their efficiency can be pretty hit or miss at Cedar Fair and Six Flags parks (if SF parks indeed have any, which is rare). I've seen way too many rows go unfilled even with groupers this summer. Some of that is on idiots who just stop and gawk at the station when they get to the front, but more of it than I'd like is groupers not being on the ball.
They're not necessarily the be-all end-all outside of Disney & Universal, and frankly, most of the time you don't need one unless you have a station that is exceptionally poorly designed (Viper and the former Iron Wolf, both at Six Flags Great America, would benefit/would have benefitted from them tremendously. Alas, Six Flags...). If the groupers aren't even consistently good enough to fill every row, then what's even the point?
Most parks around the country get by just fine without groupers. I'll never forget the HYSTERIA! of one poster on DisBoards who was freaking out about going to a non-Disney/Universal park when OMG THEY DON'T HAVE A GROUPER AND YOU CAN SIT WHERE YOU WANT, THE HORROR! It just betrays the person as someone who has no idea how non-Disney/Universal parks operate most of the time.
