We have been using this since 2010. It is relatively inexpensive, yet highly customizable from an administrative standpoint. Every page can be changed, fields moved around, terms/phrases altered. You can customize the look and feel with a bit of html code. We actually rebranded it with a new logo and rolled it out as our global ticketing system. It is basically a shell, that you can manipulate and customize to work for you.
You can create your categories, subcategories and third level categories for detailed reporting options. It is also more than just a ticketing system. You can add modules to access SLA/SLM, Asset management and Patch Management, MDM, Monitoring, Tasks and Projects, etc.
I do find the Tasks and Projects module extremely useful. Setting up projects, with multiple tasks that open service requests automatically when they are due. The asset Management module allows me to enter my warranty expiration date, that I can then create a rule to open a ticket 30 days before expiring so I can review the device and determine if I need to replace anything prior. The amount of information the agent pulls from the assets is very handy as well. It will tell you every piece of software installed on the device, how much memory, hardware specs, etc.
Customer support is mostly outside of US and can be difficult to track down. The first few years, it was as if every time I called they were on holiday or closed. It has improved 100% the last year or so, but still one of my least favorite areas (good thing about it is... I usually only have to call them once a year). The reporting templates are good, but I usually pull the data out of them and paste into my own excel document to improve the look and quality.
Since it has been in place for 5 years, I can pull reports to show yearly trends. I know my busiest month every year is January and July. I know, our company as a whole receives more print related tickets than any other issue. I can see reoccurring issues/trends. I can pinpoint locations that have constant ISP outages that may lead to a decision to find another provider.
It allows me to track, record, and pull information based on how I have configured it. I can then take that information and make decisions to improve IT, customer service, end user experience or guest experience.