Oft overlooked
With the eye on entertainment these are aimed at, it is often overlooked that the 55" are exactly the same as four 1080p monitors. They really make your spreadsheets pop, it's enough desktop space for developers to have all their tools open, you can work on photos with a better eye for details and the big picture.
If you will remember when we went to larger screens and higher resolutions years ago, going back felt like building a ship in a bottle, or watching a game through a knothole in the fence. So too this.