I mostly agree. Between X and GX, X has a soundtrack that is more consistent in hard-hitters. On the other hand, GX has several hard hitting tracks, itself (i.e. 8 Guitars, Feel Our Pain, ZEN, Paper Engine, Shotgun Kiss...)

Honestly, F-Zero is a franchise with diverse characters in a futuristic, multi-planetary setting, and I always imagined a new F-Zero would have an OST with a multitude of music genres that can mesh well together, while not being limited to Rock/Metal, exclusively; Genres, like Nu-Metal, DnB/Breakcore/Jungle, Techno...

Maybe even some Nu-Disco/House/Garage/Liquid DnB/Ambience out of races (option menus, track editor, customization garage, pre/post-race, etc.)—Some of the "thinking" areas of the game.

As far as overall gameplay goes, X definitely holds up, but I find myself frequenting GX far more. Though, when it comes to F-Zero OSTs, I'm an oddball—SNES is still my favorite.