Was a little disappointed with the picture quality. I mainly used with Amazon Prime, and while the 4K library on Prime is still on the meager side, even those movies available I was not overly impressed with the quality. First, I found that having the Firestick resolution in Auto mode, it almost never delivered movies in UHD and often fell back to HD. After setting the Firestick resolution to 4K, it did better at streaming in UHD, but even then it just wasn't as good as I expected, maybe slightly better than an HD stream. No WOW! factor at all. The stick says it needs a 15Mbps connection for UHD, I have 50Mbps service and from my lappy typically get 40-60Mbps, even on my phone I get near 30Mbps WiFi service on speedtest. Maybe it's just the Prime content that is simply not the best and not the stick's fault, not sure.