The ASRock X870 Steel Legend WiFi is the objective winner of this comparison, securing more total spec victories across the evaluated fields. Its most significant advantage is the inclusion of M.2 slots, which offer a 100% increase in capacity compared to the alternative. This hardware superiority makes it the more robust choice for users prioritizing high-speed storage expansion and overall feature density within their system build.

Users who require maximum storage flexibility should select the ASRock X870 Steel Legend WiFi to utilize its doubled M.2 slot count. Conversely, the MSI PRO B850M-A WIFI is the better option for those who specifically need additional PCIe x1 slots, as it provides a 100% advantage in that category. Choosing between these two motherboards depends entirely on whether your specific configuration demands more internal drive connectivity or increased peripheral expansion via legacy-style slots.