Here are my opinions about these Floorless Coasters
Now I was very lucky enough to get to ride one of these last year, That One being Kraken at Sea World,Florida. Now talking about the floorless effect, it really dosnt add that much to the ride, I personally think its one BIG GIMMICK, you really only get to experience it fully at the front, but I still think the effect is quite clever, You get some marvolous Foot choppers especially around the loops. And I dont know if it was just Kraken, but I found this floorless coaster to be amazingly smooth, I didnt get bumped around at all, even at the turn before the corkscrew.
They also have intensity, Sit in the back row,far left seat of Kraken, and you will experience one Amazing Ride, I actually almost blacked out coming out that Cobra Roll. Not sure if its just on Kraken though.
All in All, Floorless Coasters are Good, but Not Amazing, Just a shame you really have to sit in the front to really appreciate this effect to the ride.