Got mine today. First impressions:
1. Yay for putting both batteries in the remote in the same way. It's a small thing, but it's one of the things I love about modern technology. Also, it's hilarious how much bigger the remote is than the stick!
2. Booted up, hooked up to my wifi, downloaded updates for maybe 20 minutes. Booted back up, installed the updates. The update must have overwritten my wifi, had to punch it in again. Then it booted.
3. GUI looks like Plex...exactly like Plex, right side to the orange text. It's a complete ripoff, but in a good way - very snappy.
4. It knew who I was when I booted in. I'm not sure how. I didn't have to punch ANYTHING in, which was both convenient & creepy. I'm not sure if they guessed at my wifi network & IP (from previous connections on my Roku via the Amazon app) or had a serial number on the device or what. Cool, but weird. It asked if it was me (my name) or not - I selected my name & it booted right in, no password required. Didn't have to hop on my smartphone or computer to register it. Neat, but I'm curious how they did it. #nsa
5. Got sucked into watching the 5th Element on Prime Video for awhile. Loaded fast, played smooth, picture looked good. I am a meat popsicle.
6. It did crash once on me & rebooted the whole thing automatically. While I'm not happy that it crashed, I did like the automatic reboot - my Roku 3's occasionally freeze up & I have to manually reset the power to get it to boot back up. I also understand that it's very new & I know how programming deadlines go - ship now, patch later.
7. Music & movies sound great. I recently got a 2.1 Vizio soundbar and I was rocking out with the music.
8. I don't like the music interface. I have a few hundred artists/albums/etc. on Amazon (I always jump on the random freebies) and it just lets you scroll from left to right...which takes forever. Maybe there's more to the interface, I'll dig more into it as I spend more time with it.
9. It had a Sonic the Hedgehog game, which I downloaded, but it said it needed the wireless joystick controller to play it. Oh well. Might get one in the future, especially if apps can be sideloaded. Looks like the PS4 controller (Bluetooth) may be a good option as well.
10. Haven't read anything about sideloading yet. Specs comparison in the meantime:
http://sideloadfiretv.com/fire-tv-vs-fire-tv-stick/
12. Oh, and when it first booted up, it had a cartoon video tutorial. VERY nice for non-technical users.