Anandtech bench and gpuboss aren't particularly useful for anything other than a vague idea. Comparisons need to be made on the latest drivers for both cards. The 580 and 7870 on recent games will trade places depending on the game, but the LE is a higher end card and is overall ahead. I would stress that 2GB is going to become very important in games, already some want that much for higher settings. The 580 is going to become very dated very fast. OCUK has an LE at £155 including Far Cry 3, Tomb Raider and Bioshock Infinite. These could be sold for at least £20.