Probably because the C8 is modded for throw and triples for flood, the bigger reflector of the C8 accommodates throw and the smaller head of the Sx starts out better for flood.
Somebody posted a review of a triple that looked like a C8 on steroids with cells in series. On the phone now, will look for it later
Edit 2
Here you go there must be a written review also bit it gives you a start.
Look at the head and tail, no arguing this looks like a bigger C8.