I'd go with the YSL Lou. Just personal preference.
But it really depends on what you're looking for. Both those bags can be dressed up or dressed down, but I would say, the Antigona is a lot more casual and has a bit of a 'grunge' feel to it. In other words, if you're more of a chunky boots girl, go with the Antigona; if you prefer pointy-toe heels, go with the Lou. However, either of those bags can be worn with both these styles of shoes, so it really is a matter of which one you like better.