It's great. I had a Roku 2 and an Apple TV already, but the Roku was old, past its prime, had some streaming issues with PS Vue, and has a terrible PS Vue interface. The Apple TV does not have PS Vue, unfortunately.
I was hesitant to get the Fire TV because I've had such a good experience with the Roku, but supertux convinced me that the Fire TV's interface was so much better. We've had Dish for like 6 years, so if I was going to cut the cord I knew I needed a better interface than what the Roku provides.
The PS Vue interface in the Fire TV is way better. It has a guide like feature, is very fast, and you can even have a previous channel function. It will never match Dish's guide, DVR, or ease of use, but it's pretty good. Much better than any cord cutting option I've come across. I was really worried about not having something reliable during football season, but I'm feeling pretty good about this setup and how it's performed so far. Keeping my fingers crossed.