Single Status Update
As I alluded to earlier, my 7700K wasn't long for my main rig.
Admittedly, the 3600X is a kind of weird upgrade. More expensive than the similarly-performing 3600 non-X, yet it's still "only" a hex-core. Yet it's faster than a stock 8700K and much cheaper. I got lucky and found an ASUS Prime X470-Pro that was Ryzen 3000 ready and an open-box kit of G.Skill TridentZ RGB DDR4-3200 (2x8GB), so for about $440 all-in I've upgraded. That's about $200 less than what it cost for me to get my 7700K, Z270E Strix and the 2x8GB kit of 2400MHz Crucial Ballistix Sport LTs that I had back then, for a ~45-50% bump in multi-core performance and a fair bump in single-core performance (I ran my 7700K at 4.2GHz most of the time to keep the system cooler, though at 5GHz it's faster single-core than the 3600X.)
I'm impressed so far. The system has performed well without fault. I am a bit disappointed that the boost speeds are not as advertised though, as even with the beta ABBA BIOS, my chip won't boost above 4.1GHz all-core or 4.3GHz single-core. Maybe time will tell, or maybe a better cooling solution will.