Wildfire also has these reclined/elevated seats so that your feet do not touch the ground.  Of course, the Wildfire seats have OTSRs, but they still don't allow a person of average height to touch the floor during the ride.  I can't remember for sure, but I don't think this is the case on Kumba or the Hulk.  I guess B&M decided to try something new. 
 
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Mamba--One of the Tallest, Longest, Fastest Roller Coasters in the World 
 
Adam Rentchler