The story of course we're talking about is Dispiteous.
http://chooseyourstory.com/story/dispiteous
Chris and Fazz thought it was worse than Love SICK
Kiel didn't think it was as bad as LS (And then went into a pretty detailed response)
It depends on your point of view I suppose. IBV's story involves playing as the victim who is also a little girl. The brutality that can happen to a little girl and her entire family probably makes it darker since it isn't played for laughs.
LS on the other hand is reveling in being a complete psychopath which to some people might actually think is worse. LS probably gets slightly more graphic in parts, but since its over the top it's more funny than anything else…well to some people that is.
Her other story Atramentous...
http://chooseyourstory.com/story/atramentous
is probably a better horror story, but I enjoyed her other one more.