It doesn't affect security, they're already in browsers' trust stores. It does affect availability, but only because (the last time I checked) WoSign's OCSP responders operated from China only. To address network latency issues with your users located far away, make sure you have OCSP stapling configured on your servers.
Maybe availability but as long as you generate the private key part and paste your CSR on the website they can at worst revoke your certificate. So from a security perspective they're not worse then the others.
