Not very noticeable on phone, but in a laptop 4K looks sharper... not a good enough bonus if memory space is your priority, so go for a 720/1080 version, or use handbrake for conversion... heck, there are some 1080p vids with 2GB+ size, so converting to lower the bitrate is a good option.I'm curious, do you actually notice the difference between 1080p & 4k? From a normal distance, without squinting really hard? The only difference I can notice is 4k's being a minimum twice the size of 1080p.