[Stephen]

I think 99% of all new TVs are smart ones these days. I prefer using their built in apps over the stb ones. They tend to load faster and have fewer issues.

I'm currently on a 2020 Samsung 55 QLED. Prior to that my 2011 Samsung 46 inch 3D LED is still going strong. I tend to go for the higher cost top spec ones as they definitely last a lot longer.

HD tends to be 1080P meaning full high definition. 4K and UHD are the same ultra high definition or 4k resulting is a much higher pixel count giving a sharper image but unless to sub to any streaming with those options your best sticking to HD.