I have the Padlock and adore it to bits. I would not say that its an everyday bag at all. The chain is quite heavy (which I actually like), and the bag itself feels really dressy. I like it for fancier occasions. And I agree with Cherries, it's a more rare bag, I dont think I've seen very many people with it at all.
To me the Dionysus is more casual, likely because of the tarnished silver hardware.
Both are gorgeous bags, you just cant go wrong!