It is quite user friendly to use and has a lot of very useful features that makes the analyst/technician's life easier. From an Administrator's perspective, it has a lot of legacy code and table structures in its database that makes managing it, or pushing it to the limits of its capabilities, sometimes challenging. That said, if you have a locally installed version, the range of customization is impressive.
The Graphical Business Process engine provides a huge amount of flexibility and automation, and is one of its best features.
It has allowed us to bring call logging, change management and CMDB management into one tool, as well as providing a useful customer portal at the front end, so customers can log their own requests.