I like how it forces me and my team to attend to the tasks at hand. We can see all of the requests formerly in disparate emails in one location, and how long they've been there.
I dislike the UI of the system. I often have users that don't find the ability to select the correct category for their helpdesk requests. My users often just select the first item on the list, which hurts the reporting features that we use on the backend to see where our biggest issues exist and how our resources have been allocated (by issue type) and how to better allocate those resources in the future.
You need buy-in from managers, and the authority to sometimes force your users into using this or any service desk type solution if you've never used one before.
I often have to have my user go back and put in the issue after it's already been solved as a record for posterity when they still bring an issue to me directly, or send an email outside of the system.
To make it easier for my users, we also turned on a feature that let's them send an email (after they've registered) to a 'email@example.com' email address.
I am solving the problem of issues, problems and requests falling through the cracks!
Now, I not only get an email:
I have a dashboard, where all of my issues live
I have a timer that tells me how long this issue has been made known to me (which I can gamify and see how quickly I can clear out my issues
I get feedback from my users after I mark their issues as resolved
I have quantified data to show my mangers how I spend my time and where I may need more resources.