I don't think being fully decentralized truly matters, having a centralized checkpointer can often be better since there are many people that work in a decentralized fashion but could be trusted enough to manage the checkpointing. IMO a centralized checkpointer is better than a decentralized currency with an open attack vector.
no way. I prefer old-fashioned POW over anything POS with a centralized checkpoint.
Let's not get off topic about which implementation is better, I prefer Proof of Stake but also like decentralization and open source so this is very good research for me for helping to solve possible exploits.