If they don't tech, it's a fine option. The hitbox is not that great lined up against some upBs (it doesn't hit low/far enough out, and some upBs will just beat it) but you have a lot of leeway with the timing, so you can cover a few of their upB timings.
One thing/trick I do really like is that at lower percents, it's untechable. The non-end hits of dsmash also have pretty set stuntime. This creates a killer combinations against fastfallers, as they will be pulled into the stage (but unable to tech) and by the time they get out of stun they've fallen so far that they can't recover (or in fox's case, get edgehogged). This is especially brutal against falcon, as his awful upB goes too high and he can't avoid getting hit by this (if he ends up offstage at <15%ish and chooses to recover low).
If they do tech, though, you can't really follow up with anything. Especially if you hit early in the dsmash, they'll be able to get to the edge or counterattack before you can do anything else, as dsmash has to finish its animation.
