Did he use to be able to do 12-db3...it seems I can only land 12-df3 now
How are you using it? As a punish?
121~DB3 still combos in the corner and is still good for a healthy meterless punish. 37% IIRC but it includes the tricky D3~slide ender.
Midscreen though you should always be punishing with F4 for optimal damage.
*edit* Thinking more about it (it's been a while since I've played), you can still punish corner wakeups with F4 into 34-38% depending on your combo if you don't have enough faith in 121. I just liked to use it to switch things up a bit. Plus, it's swaggier.