If you don’t need the higher-end features of the Apple TV 4K and want something with a lower profile than the Roku Ultra, the Amazon Fire TV is a great pick. Also updated in late 2017, the new model is smaller, faster, cheaper, and offers full support for 4K and HDR content.
If you’re updating from an existing Fire TV, there are some changes to be aware of. The most positive is the addition of HDR. It’s only HDR10 and not Dolby Vision—weird since Amazon Video offers Dolby Vision movies—but it’s better than nothing.
The box itself is smaller, and it now hangs off the back of your TV out of sight. The biggest loss there is it no longer has an optical audio or an ethernet port. Amazon offers a $15 adapter that lets you add an Ethernet port. You can’t add wired internet to the Fire TV’s closest competition, the Roku Streaming Stick+ (also $70), but taking away a useful port and charging $15 to add it back feels absurd—especially given how tricky streaming 4K/HDR content can be.
The Fire TV’s biggest advantage is its inclusion of the Alexa voice assistant for voice searching. Roku, Amazon, and Apple all offer this—with Roku arguably doing the best job at finding content via your voice—but Alexa can do so, so much more like set reminders, control smart gadgets, or re-order you popcorn. You can even use a nearby Echo to control your Fire TV hands-free, though this was very hit-or-miss in my home.
In terms of the interface, the Fire TV is frequently knocked for putting Prime content front-and-center. Though it does that if you're a prime subscriber, Amazon has found a good balance. The hero images at the top are frequently dedicated to Amazon Prime, but your most recent apps are the first thing you can access. If you don't have Prime the interface is similar, though you're still shown popular Prime shows and movie rentals.
Overall, the Fire TV is a fine alternative to the Roku, especially if you like the form factor but want to add Ethernet, or if your home is all-in on Alexa. Otherwise, we'd generally recommend stepping up to either of the top-end Roku models.