The Firestick and Roku are both very cheap if you ask me at $40 and you get a lot out of each one. The two differences that I notice (and I’m sure there are many others depending on what you ultimately end up using it for):
Roku: Only Roku has VUDU. This may not be a big deal to many but back when Blu-Ray’s were still the main way to buy a movie, if it came with a digital copy then it went to VUDU. Many studios, including Disney, participate in Movies Anywhere which means it also transfers to
Amazon, Google, Apple, etc. But Paramount does not participate so if you want your digital copy that came with a Blu-Ray from previous years then it’s only on VUDU. Likewise, any $2-5 disc-to-digital conversions stay on VUDU only if they are Paramount or another similar studio.
Fire: We use their cloud storage. I also have all of our Disney-trip videos on the Amazon cloud. The kids like watching the Disney videos. Amazon Photos is only available through Fire and not Roku.
We setup our own version of Movie Night Under the Stars (movie outside). I got tired of unplugging the Roku or Firestick (I know, it sounds petty but you gotta go untangle the cords and get behind the TV)...anyway I bought a second Fire rather than a Roku to keep with the projector stuff.