What actually matters in a registrar long term? (1.Viewing)

I'm running domains for multiple clients now, and I'm starting to realize that what sounds good in the beginning isn't always what matters later on.

What have you learned to value in a registrar after working with them for a while?
What makes day-to-day management smoother (or painful) once volume grows.

Number #1 for me a personal contact, especially if you have hundreds of domains.

We have only had that a few times and to date @FM has been, and remains the best rep I have ever seen in the industry.
If anything I think he showed how an active rep, listening to domainers needs made a massive difference in the perception of the company.