Tried this out in training today and noticed a few things.
1) It's the same input as in brawl although I had to slow down to 1/2X speed to do it correctly because it's near impossible with 3DS controls.
2)The actual sliding created by the DACUS is less than that of brawls, a lot less (maybe 1/3 the distance).
3)On that note, I found that there were 2 different DACUS's, one with sliding and one with none at all. By the looks of it, the faster you do the input, the more distance you get out of it.
4)If you land the dash attack on an opponent it's A LOT easier to input the DACUS. However, it's still very hard to get a slide out of it. So far I've only been able to input the DACUS at 1X speed using this method. I could only slide on this one at 1/2X speed.
5) Sorry for being disorganized but another note on sliding. If you continue to charge the U-smash during the DACUS you will travel more distance. It seems that once the U-smash is executed it stops your momentum right in it's tracks unlike in brawl.
Curious to know what you guys discover with this and someone with quick fingers get in here and try this out.