This is the problem with EA's sliders, but 2k's work quite well.
EA's existing sliders do weird things sometimes, and only have a few positions (0-6 iirc).
The big one I remember is the shot blocking slider. Turning that up seemed to also impact the goalie as well, which is not what people want. We want the D to block more shots, but not make the goalies any harder.
Their sliders just seem "weird" sometimes and don't do what you expect. While 2k has a ton of sliders, they all do mostly what you'd expect. Turn speed burst to zero, and you get no speed burst. Turn the goalies down, and you get more goals.
Most of my complaints with 08 could be solved with more sliders. And as was said, separate sliders for human and cpu.