How do you define advanced? Is it complexity? Is it superiority? Is it the looks? Is it a bunch of intricate moves? What? How do you verify this claim that XYP kung fu is more advanced than 18DP? If it is the wonderful and myterious techniques of XYP kung fu then what about all those DuGu formless theory crap? What about all the simplicity over complexity shit?
If you want to compare XYP kung fu with 18DP then do it the proper way, by comparing it with another palm or hand technique at least. How bout the TS6YZ? Do you think TS6YZ is better than XL18Z? Do you think it is more powerful? Which one is more effective?
What about 6MSJ, arguably the best attacking skill. Is XYP skills more advanced? What about DuGu Heavy Sword technique?
What can be said surely about XYP elite skills (not ALL the skills) are that they are certainly highly advanced, very effective and mysterious. But thats not to say they are any better than 9 Yin or 9 Yang or YJJ.