[toenail]

> PoS is a sure way forward

No, PoS is a total failure. As it is not tied to reality the history of the ledger can be modified at will. There is no independent way of knowing which chain is the "real" one. There is no independent way of knowing which "validators" are valid. You can not leave the network and rejoin and be sure about the history without trusting some third party. This is the problem that PoW solved and PoS doesn't.

[dleeftink]

What would then be a more optimal trade-off compared to current implementations, in your opinion?

[toenail]

I'm not sure what you mean by your question. PoW solved a problem no other known system solves. There is no trade-off here.