Eth is probably better, don't forget that XMR has huge fees! Have a look at the side by side comparison for your setup
http://www.MyCryptoBuddy.com/path?hardware=custom&selectedCoins=ETH,XMR&Ethash=135&Equihash=1100&Cryptonote=3450&powerEthash=750&powerEquihash=750&powerCryptonote=750
http://www.MyCryptoBuddy.com/path?hardware=custom&selectedCoins=ETH,XMR&Ethash=135&Equihash=1100&Cryptonote=3450&powerEthash=750&powerEquihash=750&powerCryptonote=750
Cryptonote powers usage is not accurate. It should draw power less against ethash. It's use the lowest power for those three of that algo.
My rig (Voltage offset @ -15)
ETH (27*5) Power usage 660W-670W
XMR (700*5) Power usage 460-470W
http://www.MyCryptoBuddy.com/path?hardware=custom&selectedCoins=ETH,XMR&Ethash=135&Cryptonote=3500&powerEthash=670&powerCryptonote=470
Looks like XMR is your winner, but ETH isn't too far behind