HRD is pretty much spot on about it depending on the player:
The general heirarchy of precision is this:
Hitbox>Arcade Stick>Pad.
While hitboxes are technically the best, very few players have put in the large amount of effort required to play them and even fewer use them competitively.
I myself was a pad player, but nowadays I only play siegfried on pad, every other character on every other game I use stick.
Bear in mind though that Soul Calibur is a game you would never need a stick to play at high level, it is purely an optional thing.
The general heirarchy of precision is this:
Hitbox>Arcade Stick>Pad.
While hitboxes are technically the best, very few players have put in the large amount of effort required to play them and even fewer use them competitively.
I myself was a pad player, but nowadays I only play siegfried on pad, every other character on every other game I use stick.
Bear in mind though that Soul Calibur is a game you would never need a stick to play at high level, it is purely an optional thing.