I have a Firestick(low end) that's a couple of years old, but I'm about ready to ditch it. On one hand, at least Amazon keeps the OS reasonably current so that it works with with all the new streaming service(unlike my dad's Smart TV that won't work with the current version of any streaming apps beyond Netflix). On the other hand, though, I find navigation on it really slow, clunky, and sometimes frustrating.
The Firestick is really amazing non-intrusive. As it is now, I have mine dangling out of one of the HDMI ports on the back of my TV, and power it via a USB port also on the TV. It works with the HDMI control protocol(HDMI-CES?) so I can control it with the TV remote rather than the small and easy to lose dedicated remote. It's also small enough that I often toss it in my suitcase when traveling-if I want to stream in the evenings or whenever, it beats the heck out of a couple of people crowding around a laptop or iPad for that. I just toss it in the ziplock bag with my phone charger, computer charger, and raiser charger.
I've been halfway shopping, and an Apple TV would be my current choice given how much I'm integrated with everything else Apple. For one thing, though, it's really easy to talk yourself up from the ~$140 starting price to $170 and then $200, and at any of those prices I don't want one badly ENOUGH when I have something that's at least functional now.