I read this a few times now, but what exactly do you mean with slow? Slow moving, or long startup until a hurtbox appears (or both)?
edit: oh my god, looking at the video, DKs fair looks SO much faster than in Brawl, it'll actually be useable not only once in a blue moon. This is awesome!
Does anyone know if DK can move backwards during his grounded upB?
The speed at which you move forward while rolling. It starts up quickly enough to have some good uses, I just don't think it's going to be used for closing gaps against characters with good ground games. I kinda wanted it to be another approach tool, besides the SH double Bair, which I was told is back in. I didn't try to go for double Bair, myself.
Fair is faster, but it still has the iconic (and awkward) windup, so you still have to use it a little ahead of when you'll actually need it, same as always.
I never tried to go backwards with grounded Up B, but I will check it out on Saturday! That's actually something I wanted to try that I thought about after leaving Best Buy. The hitbox for grounded Up B seems to heavily favor DK's facing direction, so I'm not sure what to expect. I didn't manage to land the first hit of the move on anyone, either. You know, like how the starting hit of Spinning Kong acted like a moderately powerful punch? Not sure if that's back or not.
I also really want to try and spam the aerial Down B, to see what it can do. I only ever used it on the 3DS version, since that was single-player and much more controlled. To me it looked like a clap, not a slap, but it might have been the tiny screen... or maybe the different versions are akin to the Custom Moves - one for WiiU and one for 3DS? Seems unlikely. Guess I'll see.