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.
No, you may want to re-watch it. More specifically, Ethereum will be a hashimoto dagger IO bound PoW consensus mechanism.
The latest under review is here under PoC7:
https://github.com/ethereum/cpp-ethereum/wikihttp://gavwood.com/Paper.pdfYes, I agree it is confusing being that Vitalik has gone back in forth between slasher and dagger and the fact that he may eventually switch from PoW to a weak subjectivity TaPoS slasher algo, but for the time being and for distribution it is ASIC resistant PoW.
Read the paper above to verify that it is indeed PoW.
Additionally, there are tremendous differences between PoS and DPoS. NxT and Bitshares have a different security model and concerns. Nxt is slowly evolving to TaPoS model of security which is still much different that DPoS.