It seems to have a history of having fewer exploits that can result in leaking data. It has had more DoS exploits (I think) but most of them could be mitigated through configuration.

I think that the revenue model for Polar has put more money in to making sure it is secure. OpenSSL has always suffered from the fact that it is mostly "leach Ware". People use but they don't contribute because it isn't related to their core competency, so they don't mod or upgrade it. Polar on the other hand has people paid to test, patch and maintain the code.