Shaya actually made a good point about SDI and jumping once.Yeah I forgot that.
However, tap jump on gives you the possible risk of eating your jump in certain scenarios when you just wanted to use up as an input of SDI.
However, as a player who played a loooot of Melee before Brawl, I just got used to it being on
Basically, jumping might be better in these situations.This is actually a good point, and it does occur on occasion with SOME moves. However automaticly jumping through SDI actually GETS YOU OUT of a lot of things. And SDIng up (i.e. half circle or quarter circle motions) dont have me jumping instantly either... Because you are STILL GOING TO BE IN HIT STUN AFTER BEING HIT BY MOST MOVES; enough time to NOT buffer a jump (which if you were doing qcdi wont happen as the up input was already read and will be ignored until the stick is returned to perfect neutral).
Also, I will admit that during times that you want to up B or uair without using your jump, occasionally you may lose it due to being overexcited or anxious in the moment, but as you play more, the chances of it happening gets smaller and smaller. It gets even smaller if you become a seasoned Smash 64 player because the controllers are so **** sensitive.