This is like one of my favourite dresses. Normally its something I'd wear with a coat and boots rather than heels, but I've worn it to a few parties. I think the seamed tights add a touch of retro, but also sassiness. Takes away from the twee-ness. Again, I don't know if its a 'bit much'. So let me know what you think!
I really like it. I agree that the seamed pantyhose add a little vintage appeal. You have great legs, though, and I think the leggings and pumps show them off nicely and tastefully. Wear it when it's okay to attract some attention.