Yup, timing is different on hit and block, you just have to be good at hitconfirming the f2,2,df1 and not be too hasty on the dash cancel input (otherwise only the f2,2 comes out on block, and you're unsafe). Bug cancelling f2,2 into 212 is super tight so I don't bother, but I don't really have any problems hit confirming, then cancelling into 1,1,b2 on hit and 1,1,3 on block. I use D'vorah's nonsensical shouts as an audio cue to dash.
"Xbox Four!"
"Kentucky Fried!"
EDIT: it's probably possible to buffer the dash for tight strings and still be *relatively* safe on block with an optionselect. Just stick a 4 somewhere in your string and you'll get your bug cancel on hit, and a 2,2,4 on block, which is only -7. No way in hell I can do that on my PS3 pad though.