Actually I do not understand all this hope in the new VEGA architecture. The first benchmark showed 300W power usage and doubt they will do 60Mhash con ETH, which is less that what you can get using current AMD cards
So if you don't understand then that makes me much smarter than you, okay, first polaris is done for right, hashrate is decreasing, amd even claymore or other people dont know if they can fix that, second Vega is a new arch which means problems like we see on polaris might not affect Vega, Vega will have gddr5 versions, will not be only hbm2 versions which mean, Vega is the only thing to make a case and compete x nvidia 1070 concerning miners, they will probably place it around gtx 1070 price, that is a reason amd will not fix polaris, because amd want miners and gamers to make their vega arc a success.
Remember, after polaris is done which will be in 3 or 4 months then to match or surpass the gtx 1070 in hashrate will only be a Vega + gddr5.
Concerning power consumption, performance/power, lower vega models with gddr5 might not use that much power.
lol amd wont using gddr5 on their vega, only hbm, they architect only design for hbm, vega with same count core with fury line, which 60% faster coreclock and 100% faster memoryclock than fury, vega is the beast for next 2years from now
i think amd design vega for zcash, eth will switch to pos , nobody post zcash benchmark lol