I believe you can get 300 H/s at 100W or 370 at 150W. I can't confirm as I don't own any. Also, Claymore is AMD only.
Yeah, that probably sounds more realistic... If that is the case, it would seem the 1070 is only a little more efficient than the RX 480.
RX 480: 100 watt consumption / 230 sols = .43 sol per watt...
GTX 1070: 150 watt consumption / 370 sols = .41 sol per watt...
Now, I guess for someone with a huge power bill, that would make sense for multiple rigs. But on my end... With only about 4 cents per kilowatt hour, I would need to get a 1070 for $350 or less to meet the same ROI as an RX-480. Plus, I only have two rigs.
I guess for multiple rigs, high power cost etc, it makes sense to go with 1070's. Less power consumption, more hashing power on a single rig (less boards, CPU and RAM to buy, etc... Not so much for me though, at least at the moment... Though if I could find a 1070 for $350, I'd buy several in a heartbeat considering all those factors...