Careful. "Pure POS" is a "pure piece of shit".

There is a reason that real projects like Ethereum are taking a long time to get this right.

Proof of stake protocols are vulnerable to two major issues:

• Long range attacks
• Nothing at stake problem

There is no consensus protocol that really fully addresses both of these problems. Tendermint is pretty close but Ethereum's Casper is designed to value availablity more than consistency.

Soooooo long story short, this is a whole load of crap unless they can solve those problems.

Casper and Ethereum are close but PoS is still rather untested.