Pubmatic has a very clean interface and the reporting is very flexible. It's one of the more modern-feeling interfaces that is really a joy to use. You can pre-select reporting dates, define a certain date, or define a flexible date range.
The Pubmatic staff is excellent to work with - they are very attentive and do what they say they are going to do. We have an account manager and a backup email list so that the whole team is aware of our issues. Review collected by and hosted on G2.com.
We did not set up our demand segments, so I do not know too much about how those were setup in the interface. We are somewhat at the mercy of their expertise for this area in their interface. Review collected by and hosted on G2.com.