Logistically the low light was the hardest part of getting a good shot. The cold hard light of my Canon 600ex-rt was just to harsh and cold. Sure, I could warm the shot up and up the colour temp in Adobe Photoshop but it's still not genuine and you don't get the subtleties of light from the actual carousel.
Instead i again relied on the magnificent low light capabilities of the Canon 5D MKII and cranked the ISO up to 4000. The low noise levels still impress me even after 2 years.
Anyway there was something about this shot (perhaps the child-like excitement) in grown adults that appealed to me.