XMR is the best mining option right now. 686 h/s on my Rx 480 
1235/2145
1235/2145 700-710 h/s on Rx 480 nitro stock ,temp 60 , fan 40%
Do you get any low difficulty rejects? I get about 5% rejects when I ramp up core at 1270 and mem 2100 (strap 1750) leading to ~770h/s
What are your settings?
Kindly share
-Thank you