You haven't heard? Ethereum is going to be PoW. BitShares is DPoS , not PoS. Nxt is slowly dying and losing place to PoW and Debt based currencies.
There is no fundamental difference between DPoS and PoS.
Regarding Ethereum, here is the latest news -
https://www.youtube.com/watch?v=qPsCGvXyrP4. It says that Ethereum will be PoS.