While messing around in practice I discovered two things. Given how much players SF4 has, they are probably already discovered years ago but I’m gonna post it anyway since I never heard of it:
First, I found out that adon neutral jump MK (which is usually used for “fuzzy guard” overheads) can hit crouching big characters if you hit it meaty, exactly as they are waking up. Big characters means sagat, gief, boxer, etc. Since there was no reason it was adon specific, I tried with a couple other characters.
So far the only ones that can do this (I have not tested all the characters) is sakura with nj.HK and dan with nj.LP.
Instant overheads, as you might know, are unsafe on hit but good for finishing rounds and especially good if your opponent is a hit away from being stunned. That looks very likely to happen if you’re playing sak, two BnBs in a row + nj.HK will most likely stun players, but actual real sak players will know the real numbers better.
Another interesting thing is that those same moves can also hit bigs (and probably smaller characters) in “fuzzy guard” setups. That means a normal that usually doesn’t hit crouchers does because you do it while they are in block stun. In case you don’t know, adon and juri have good setups for this because they can cancel into combos, see: http://www.youtube.com/watch?v=AX6HTskGRu0
When fucking around with this something strange happened, with sak I did an ex tatsu that went way farther than normal. I didn’t know what happened but I found out some shotos, when canceling their air tatsu into ex tatsu, get extra forward movement. The only significant effect I found was on sak and ken since they move forward by default. Ken does a weird float animation that goes very far. Especially goofy when you do it jumping backwards.
Canceling a special into ex is pretty easy, just plink an extra button after you hit your special, ie: QCB HK~MK with air tatsu.
The whole things seems pretty useless, but maybe someone can find some use out of it. Ryu and akuma seem to be unable to cancel their tatsu into ex while jumping forward, for some reason.
I tried using ground specials to see if I could also get extra properties, but it doesn’t seem to work, even with specials that propel you forward like bison scissors. Then again, I don’t have time to test all the characters, there must be one move in the game that benefits from it.
Again, I’m almost sure both things have been known for years and other than the sak nj.HK thing, it’s pretty useless, but better be safe than sorry.