Interesting. What do you think about BlackCoin?
I have a view for similar coins (NXT, BC etc). Pure POS (only-POS) looks like a deposit in a bank. It's not profitable to spend coins, and people just keep them up. Coin gain price when you became able to buy something real on it. So BC is just a vault deposit but isn't currency imo.
Also BC pools as this
blackcoinpool.com confirm my opinion.