TeamViewer is very easy to use, and I use it in a professional manner to assist colleagues at the university remotely. It's a good product for helping others, especially with user problems, installation issues, or other tasks.
It's not my primary role, but sometimes, when someone has user issues with their computer, I assist them remotely. Even though I don't work at the service desk, I help with security and other problems using the tool.
I find the mouse control and the ability to click for them very effective. I can move the mouse and click on buttons as if sitting at their computer. These are the basic features I use most often in the solution. There are tricker features that I don't use much because I don't need them frequently. Overall, it's a great tool for helping others with their computer issues without traveling to their location or another building.
It saves time because I can guide someone by saying, "Go to the third option in the menu on the right," and then click on it. I can see their screen and guide them through the steps, watching the mouse move and seeing everything that happens on their computer.