OCC has published a review on the OCZ PC3-12800 OCZ3X1600LV4GK Intel XMP 2x2GB

At the 1750Mhz maximum speed, I could run the modules at the same 8-8-8 latencies. This set of OCZ modules allowed me to go as tight as 7-7-7 at 1622MHz, so you can get a small bump in system feel and performance. The price point of $142, which these modules will be offered at, is higher than most of the currently available sets of i5/i7 P55 specific memory kits by between $15 and $35. This set of modules most likely won't be for the enthusiast, but for the mainstream user looking for a step up from the 1333MHz kits on the market. There are kits with more overhead available for the enthusiast for a lower price, but when it comes down to no fuss overclocking of the memory, the XMP profiles prove beneficial and offer an increase in performance without the headaches.

OCZ PC3-12800 OCZ3X1600LV4GK Intel XMP 2x2GB Review