The ASRock X870 Steel Legend WiFi is the objective winner of this comparison, securing a lead in seven out of fourteen evaluated specifications. Its most significant advantage over the competition is the inclusion of PCIe x16 slots, which offer a 100% improvement in capacity. This hardware configuration provides a clear edge for users requiring superior expansion capabilities for high-bandwidth components, establishing it as the more robust choice for systems demanding extensive connectivity and future-proofing.

Users prioritizing high-performance expansion should select the ASRock X870 Steel Legend WiFi to leverage its superior PCIe x16 slot count. Conversely, the MSI PRO B860M-A WIFI is the better option for those who specifically require more PCIe x1 slots, as it provides a 100% advantage in that category. Choosing between these two motherboards depends entirely on whether your specific build configuration relies more heavily on primary x16 expansion or secondary x1 slot connectivity.