Firstly filter by comparative products using the "ROG Core" drop down box. Your notebook will not keep up with the 5+GHz Rampage systems on page 1, it's physically impossible! So don't worry 🙂 You can compare your result against others by selecting two boxes on the left.
Each successive generation of notebooks will get faster - that's the progress of technology! - but the fastest G75VW is ~53000, so your 51000 is certainly not far off!
Things that can improve your score marginally will be lower latency memory, your SSD and a 'clean' Windows install. You can OC your graphics card a little and maybe that'll improve the OpenCL score a touch, but sometimes not.