I like that CertCentral is easy to use, it has excellent documentation, and it's very flexible. The interface could be more intuitive. For example, if you're looking at an SSL cert, it would be helpful to have some sort of visual indicator as to what type of cert it is.
Also, I wish there was a way to search by expiration date instead of having to go through each individual domain. If you are looking for a quick and easy way to manage your SSL certs, CertCentral is a great choice! We've been able to streamline our process for managing our SSL certs.