"The upside to all of this is a cool running board, plus as a bonus, it's the only passively cooled X570 board on the market."
Great so it's a choice of one...
Great so it's a choice of B450/X470 vs Intel... Sorry but I'm done with those God-awful 40mm "Northbridge" fans, let alone paying $200-$300 for the "privilege" of "upgrading" to one like it's still 2006. Every single one I owned all ended up the same way - they were very quiet for the first 6 months (and thus received gushing praise from tech reviewers), then after half a year or so they all gradually started to develop a horrendous whiny noise whose high-pitched
squueeeeal was 1,000x more annoying than +92-140mm fans at the same decibel rating (40-50mm fans have far worse overall noise profile / tonality). If the choice is between suffering $300 worth of that for the sake of PCI-E4.0 benchmark e-peen vs remaining with PCI-E 3.0, blissful passive silence, 1/2 to 1/3rd of the price and practically no real-world difference, I'll stick with the latter any day...