This version is a lot less modded than I expected. The home screen is fairly Amazoned but most other things look moderately close to stock.
However - that's just Android. The lack of Google Apps, Play Store and Google Play Services is more of an issue but the seriousness of that totally depends what you're expecting to do with it.
hear from someone that have a fire phone (and who has to take it out the garbage drawer when the main phone died)
fireos is garbage. you can't have a calendar or clock widget. any widget. none.
the launcher is a joke designed by committee. you get a huge icon of the recent apps
1 huge icon at a time. which would show app data on the bottom, but not even amazon own apps use it. so it's just one big icon for you. always. from the screenshots, on this version they changed that to instead show your media hosted in Amazon's cloud. yeah, that will be useful to have using 60% of my home screen at all times.
then the reviewer says he didn't find any app missing... well that made me sure that is a paid fluffy piece (and I'm done with arstech site forever thanks to that) because besides Facebook, every app is missing. from youtube to Firefox. you get nothing but social site apps and fart apps.
However - that's just Android. The lack of Google Apps, Play Store and Google Play Services is more of an issue but the seriousness of that totally depends what you're expecting to do with it.