HardwareZone has a review up of the Gigabyte 955X motherboard, dubbed the “Royal”. 
Performance-wise, the GA-8I955X Royal was able to perform as well and in some cases outperform the Intel 925XE Express reference board, meeting our expectations for the new chipset. It also showed some exceptional performance in the hard drive subsystem testing. However, our results indicated that it could not keep up with the nForce4 SLI Intel Edition based GA-8N-SLI Royal in a majority of benchmarks, falling behind primarily where the memory subsystem was taxed the most.