Surely, the sand has other benefits. I would expect that the weight of the sand makes for a more rigid structure, allowing the trains to conserve momentum. I feel like that's part of the reason Kraken has aged a little more gracefully than Hulk. If that's the case -- and by all means, engineering and physics majors, weigh in here, pun intended -- then I'd take the smoothness over the roar any day. Hulk was to the point where I had to ride at night or else I would have a headache all day, and I have a high tolerance for coasters.