What's weird about CC/ASDI down is that in Melee, as far as I can tell, the viable characters don't seem to care too much about it : Fox and Falco start their combos with a vertical move, which isn't affected by it, Sheik and Marth mostly start combos with grabs, CF can do both, and then there's Peach whose dsmash will make you stop CCing immediately. The only time I see people CC a lot is against the spacies' jabs, and possibly against jiggs.
It seems like despite the mechanic being identical in PM, it affects a larger portion of the viable characters, and to a greater extent than it does in Melee. But that may be because I don't know **** about Melee and/or that we all kinda suck at PM at the moment, eh.
Either way, since we're talking about CC I might as well give my opinion on it. I like the idea of a secondary defense besides the shield, that is more effective, but costly. Crouch cancel is not bad imo. But in practice, ASDI down allows you to access this type of defense AFTER getting hit, between two jabs in example. And I don't like that at all. I feel like such a strong type of defense should only be available in prediction, not reaction. I feel like this makes CQC less of a thing in PM than in Brawl and I kind of miss it. My two cents.