NXT is 100% Proof-of-Stake, no inflation currency/platform. It has been in production since late 2013.
Research papers and tools can be found here:
https://github.com/ConsensusResearchIf you haven't read about it, doesn't mean it doesn't exist.
Bitcoin should draw from the Proof-of-Stake coins experience and implement a hybrid PoW/PoS to be more secure and not depend on miners so much. The sufferings will continue if users don't have any power over consensus. Proof-of-Stake coins give power back to users.
nxt's market cap is $11million dollars. It is not proof of anything.