To get the best iptv service experience in the USA, what devices are recommended for smooth streaming in 1080p or 4K quality? Is a smart TV enough, or should users invest in dedicated streaming devices like Amazon Firestick, Nvidia Shield, or Android TV boxes? How important is a stable internet connection, and what minimum speed is required to avoid buffering or lag? Should users consider wired Ethernet over Wi-Fi for better stability? What other factors, like router quality or using a VPN, influence the performance and security of IPTV streaming in American homes?