As someone playing on an Xbox One and 720p screen, what difference in quality am I experiencing?

Title came across kinda awkward. Pretty much, am I getting screwed over by having a lesser-quality television and an Xbox One (which I have heard is the least of the options to play the game on?)

If so, will a 1080p screen make that much of a difference?

Submitted by Quravin Xbox 720 Release Date 2015