Ethereum needs some ajustments but I can see it being worth about 1000$ in 2020
this is a very long way you are predicting. i don't think it takes so long to reach that way. At the end of 2018 we will see its price to reach 2018.
the way people are taking interest in crypto i think it is really predictable that after bitcoin we will see that eth is the only one which is good enough to takes its place in the near future.
The thing is that, Bitcoin will increase alongside ETH, making the price increase of ETH harder. People will think that if ETH just reached 0.5 ETH as for example when bitcoin just reached $10,000 ETH. What do you think? Isn't it will be overpiced? I guess not, but for some people, it is.
But I guess that the flexibility amount of every cryptos could handle this.