Yes, 4k is nice but it is not anywhere close to the magnitude of SD to HD.
Plus, you really need to sit much closer to the TV than people do in their home.
Take Value Electronics for example. In their showroom, the chairs are just 4 feet in front of an 85 inch screen. This is something you will not find in virtually any home.
In fact, most people are sitting further away from their HDTV to even be able to see 1080 resolution from their seat.
I have a no clue where you get that from, I know no one who has replaced a TV with an Hi Definition one and simply because its a higher res have moved back further, even if its a larger TV.
And I am saying the quality of the detail in the Samsung 4k display that I have seen kicks Hi Definition's caboose I don't care how far away I sit. The detail of people in far off distances and buildings and so forth is incredible. The problem as usual will be if producers actually utilize the full ability of it. Frankly most Hi Definition could be a lot better than it is, but they don't use it to its fullest abilities anywhere really.