I have a firestick. It does have issues yes but the reason I got it is the apps on the rokus are terrible, the tv not the plug in roku device. My living room tv is a roku tv, and I have a fire stick on it. My bedroom tv is a roku, with a roku plug in device. In both situations I got the plug in because the built in app kept hanging and telling me my wifi was too slow, the plugins use the same wifi with no problem. Generally speaking if the Firestick isn't working right I just unplug and replug and it fixes it but shouldn't have to do that.
I do agree about the interface with Prime. I still watch some stuff on it. Ironically the app I hate the most is Netflix, it takes so long to load sometimes I give up and turn it off and back on thinking it hung. But once it logs in it works well.