So I bought this cable, thankfully, after doing my research. I needed a dpi to HDMI cable to connect to my 4K tv... and I would have bought any generic cable until I found the link to a specifically 4K at 60Hz cable. It seems some 4K cables were only 30Hz... and some were not even 4K. So, getting this cable, even though it was expensive, seemed worth it.
Now I use it to mainly connect my desktop to my 4K as a second monitor... it works pretty well. The resolution is excellent... and it does not feel as if I lose too much in the second monitor. The colour of the computer display on the tv is a little extra saturated, and the text is not too bad, but when streaming video content, there is no perciptable difference between streaming through computer or through the tv directly.
My only problem was that I chose the longer 3 metre cable, when I actually needed the 1.8 metre cable. And sadly, I wasn't able to stop GFX shipping the longer size. But I've looped it to avoid a cable mess, and as I feared, it does not lose any resolution despite being longer, so no harm done.
Also... I think this cable is DP 1.2 but my machine was DP 1.4, but there has been no problem, so that's a relief.
The cable is sturdy and is very reliable so far. Ultimately, no regrets in this purchase.