The reason why SD isn't the same as PF in terms of shit missing is that,
PERFECT is it what it is; the aim of the mod is to hit all notes at the correct time, nothing more, nothing less. It means when you missed, it's obviously you either hit late, hit too early or completely missed. ALL MUST BE PERFECT, NO EXCEPTIONS.
On the other hand,
SUDDEN DEATH is a mod that makes you actually pass a song provided that you will hit all notes regardless of the score either you get a 50 or a 100, it doesn't care. what can only triggers it is that you miss.
Removing the animation and the option screen for a replay on this mod will make it a bit shady on providing a player insight and to analyze his play and see where did he gone wrong.
So, you shouldn't be just fine retrying and retrying, you should also need to study your points of failures if you're using SD.