560 are the best card for mining at the moment du to the price of 570/580
560 can achieve 15MH/s and more on ETH and more than 470H/s on Cryptonight (Depending of Memory and strap). Branko was the first to explain that.
I have 560 Micron memory Hash 15.6MH/s for less than 40W and Hynix 15.2MH/so
There are 2 kinds of 560 - 1)560(1024) and 2)560D(896)
I've never seen 560D that gives more than 13.3 eth. Have you?
Of course 560D are crap GPU. I only speak about "normal" 560.