On Friday an independent Phoronix Test Suite user uploaded to OpenBenchmarking.org a four-way R600 Gallium3D configuration comparison. From a Gateway Laptop with Core i3 330M CPU and Mobility Radeon HD graphics, the Arch Linux system was running the Linux 3.10 kernel with Mesa 9.3-devel. The individual tested the Radeon driver in a stock configuration, the same stack with R600 SB, the LLVM back-end, and then the R600 LLVM back-end with the R600 SB optimizations applied as well.
Those wanting to check out these independent tests of the R600 SB/LLVM back-ends can hit up 1308169-SO-SHADERS4516. Below are a sampling of the results where the OpenGL shader back-ends make a difference.