Yeah I understand all of that... It just seems like in many character's cases, you're better off using their P mode because there's still the combo factor... I know the timing is strict, but its not just frame strict... If you can do link c.LP to c.MP with a shoto/guile/seth in SF4, then you can combo in P mode...
I've seen a bunch of matches and mixups aren't really effective depending on the character, and there's only some who really benefit from S mode (Zantetsu, Mukuro, Moriya, Lee)... I won't even put Akari in that list just because her infinite can be done in both modes...