Ethereum minig is more decentralized due to used algorithm and mining at GPU. So it's better correspond to decentralized nature of cryptocurrencies.
I think you had a good point here mate, ethereum has its own algorithm and mining at GPU is really showing more good feedbacks. That's right its better correspond to decentralized nature of cyptocurrencies, and with bitcoin's mining feature I am certain that either of those two will have it's good future in terms of mining preferences. Actually I can't choose exactly what's the best because each parties had been performing so well as per reviews of mining investors.
