I would go with the ASUS board for really one reason... No bandwidth issues. If you read the specifications:
(Note) The PCIEX1_2 slot shares bandwidth with the PCIEX4 slot. When the PCIEX4 slot is populated with a x4 card, the PCIEX1_2 slot becomes unavailable.
Your motherboard slots are limited by bandwidth. If you plug say a PCIe X4 SSD, you want be able to access one of the PCIe x1. This may never be an issue but why limit usage of motherboard slots for a little savings??