Here's a little tip I learned from Graham Wolfe.
Boxer leans back really far when he's in the standing block position. His sprite is actually a few pixels further away than when he is crouching. So if you have your super charged, and are waiting for your opponent to throw a fireball, you can use this to your advantage to get a few extra frames.
What you do is sit in the crouching back position, as you normally would (to charge down and back). When you see your opponent throw a fireball, move the stick to the standing back position, and THEN do your super motion. You'll have a few extra frames to do the super before the fireball hits you, and a few extra frames is a big deal!
