I've had severe problems with copper cables of 3m or more. While you won't notice issues on a standard 1080p display, I sure notice them on my 4K and 3440x1440 displays. And note that while they say they are DP 1.4 if you dive into the specs, most are really only DP 1.2. I want a cable that will do 4k @ 120 + Hz and 3440x1440 @ 120+ Hz. Lindy do their gold line up to 5m but even that is over £80.