Well, the 8700K was clearly a faster CPU than the 3600, but £150 more expensive and i had the Motherboard ready in the form of the one the 1600 sat in, the 3600 was a good CPU in its own right and all together £250 cheaper for me to upgrade.
I seriously considered a 9900K after the 3600 as at that point i was going to switch the board out anyway, i almost bough one but the Zen 3 rumours just had me hanging on for a bit longer.
Post the Pentium IV i never has any issues with Intel, i really liked the 4690K but it was starting to show its age, bottlenecking a 1070 in one or two games.
All i can tell you about the 5800X is this, i turn my computer on in the morning, i do some work on it which includes high load rendering ecte.... in the afternoon around 6 or 7PM , sometime earlier i turn the computer off and go do stuff for a few hours, in the evening i come back and play games with friends.
I do that day in day out and have done for as long as i have had it, nearly a year, in that time its never put a foot wrong, nothing, it just does what it does flawlessly without complaint, that really is it, it just does its thing, kind of boring but after initially messing about with it getting stable overclocks and such i have never been back in the BIOS.