Right, I think it depends on how long you want to wear them, what your budget is and how trend-conscious you are. The left ones are a forever shoe, to my eye, while the right ones are on trend and fab in a different way.
Your body type and what you plan to wear them with might also play parts in your decision. I think the ankle strap can shorten a leg and emphasize a short-ish skirt and make it look even shorter.
Both lovely! I'm no help at all, am I??