Tech Report has a review up that looks at the MSI P965 and 975X motherboards and how they compare with one another. 

Apparent overclocking potential is one of very few differences between MSI’s P965 and 975X Platinum. Price is another, and given just how similar the boards are, I’m not sure the 975X is worth the extra $20—not unless you really want Viiv support. That’s not a knock against the 975X Platinum, mind you; it’s the cheapest enthusiast-oriented 975X board on the market. The P965 Platinum just offers equivalent functionality for less.