If you expect 480 to be faster than Hawaii, then think again
I agree with that. According to the latest mining performance of the 480 RX, it is slower than the R9 390.
Although it is slower, it is more efficient. It depends on your electricity price. If it is high, it is better to use 480.
For the high electricity price people, they should not use graphics to mine. If they invest now, there will be no ROI.
The network hash rate is over 4000G now, that is almost 200,000 of AMD R9 280X/380X. The 480X will also be added.
I think half of that is the 280x or early graphics cards and half of them are the 390 or later graphics cards.