Yes - I have one and use it all the time. I use it mostly when I am bbq-ing out at Burning Man for several thousand people and we have to meet Health Department food safety rules (very challenging in the desert, I assure you). I have to constantly monitor food temps and we are surprise inspected every day (sometimes twice a day) and my Raytek helps me with these duties and helps me demonstrate to the inpsectors that our food is out of the danger zone. The infrared is also helpful when trying to determine surfrace temps of pans and griddles (as long as they are non-reflective).
The infrared is not as accurate as a probe for checking internal temps (and even some surface temps) but it is close enough that you can tell what is going on with whatever surface your are measuring.
It is helpful during comps to show inpectors your meat is stored properly, but in my experience they really just make sure you have it on ice and it is not doctored. They never seem to care about the exact temp. I am just anal about it when comes to food safety, in order to stay in habit.
Do you need one? I would say if you are doing food-service of some kind it is extremely helpful. If you are not, it is only a cool gadget that will impress people who have never seen one for about 30 seconds. That is a pretty pricey 30 seconds. If you have one you will be glad, but I doubt you will miss not having one. (If that makes any sense.)