As we recently said, in motherboards it’s all about the features. After all, you are getting the same basic chipsets across each market segment (X58, P55, H5x, 890, etc.). Because of this the performance envelope is something like 5-10% difference on average. True, there are some extreme cases where you might see as much as 20%, but those are going to be very expensive products.
To combat this, motherboard manufacturers are finding new ways to add on features to attract buyers. We have seen these manifest as better power regulation, more PCIe slots, multiple BIOSes along with improved audio and LAN chips. Lately ASRock has been taking a somewhat different approach. As we saw in their P55 Extreme4, ASRock is working to add more SATA 3.0 and USB 3.0 ports. On the P55 Extreme ASRock broke out of the typical two of each and managed to pack in four USB 3.0 and SATA 3.0 ports.