Linux runs well on any Ryzen based CPU
Overall, the AMD Ryzen 7 3700X and Ryzen 9 3900X are very capable performers and ran superb. That is, when they could boot Linux. If it weren't for this major problem of newer Linux distributions not currently booting successfully with the new AMD hardware, it could have been an instant home-run for Linux enthusiasts looking for their next PC upgrade or replacement. It's still possible that this Linux systemd service issue might not be a big problem in the long-term assuming it's quickly rectified and some workaround exists for letting current Linux ISOs boot fine -- as opposed to having to wait until the next round of Linux distribution releases or jump through other steps like first installing the distribution using a separate CPU/motherboard in order to apply any patch/updates. But as of writing there is no easy solution and it's even more perplexing that Linux 5.2 can still run great with Ubuntu 18.04 LTS.