We've started testing the OCZ ZD-XL SQL accelerator solution. We're using 16x900GB WD Xe HDDs in an iXSystems JBOD as a baseline and comparing those results against the 1.6 TB ZD-XL (Z-Drive R4 tuned for SQL caching). SQL testing is being driven by up to 20,000 virtual users in Benchmark Factory's TPC-C workload.
We'll update this thread as we progress and are open to fielding questions or comments on the solution at large. More background information is available here -