If you are considering a safe haven, NXT requires a 91% attack. It is proof of stake though. Very interesting concept. In other words, someone would have to own 91% of all NXT coins in order to pull off an attack. It has risen from a market cap of 21 BTC to over 100,000 BTC since November 2013.
Yeah, in general NXT seems pretty good and very much under appreciated by the community at large. I don't own any but the only real criticism I see from people is them being angry that they didn't buy any at the IPO and calling it unfair because they didn't risk any of their own money on a new technology. Which of course is not a valid criticism.