We also use Endpoint.
Endpoint works in a single-signon environment, and so it automatically changes your encryption key whenever you change your Windows logon password.
I have never had any problems, even when Endpoint was owned and provided by another company (Guardian Edge, I think). Never an issue with it in either incarnation...that I know of. My biggest fears for a personal system would always be
1. getting locked out by mistake
2. being unable to manage, diagnose, repair, or recover my hard drive partitions with normal utilities
But in a centrally-managed corporate environment, we have people to take care of concern #1.
Additionally, we have centralized backup and recovery (and nobody really keeps critical data on their local hard drives anymore), so concern #2 is mostly a non-issue.