Again, it depends on the situation. Accelerated movement is better if you're going up against a slow-moving lug, but against speedy annoyances, I'd say pinning them down with gravity is better. Less movement for them, more opportunities for you.

[ To launch those sweet, sweet combos. But of course, this is assuming that Weiss's world follows Tales Logic (tm), where stunlocking is a thing and aerial combos can also be a thing. ]

The best situation would be a slow them and a fast you, but we can't always have what we want.

[ Things happen in combat. Artes are interrupted, someone breaks out a Mystic Arte, people get status effects when they don't dodge in time...etc. ]