Hot take: I dislike the direction the X series music went after X3

X1-3's OST were, for the most part, guitar-based rock tracks emulated with MIDI. Sure, they didn't actually involve any guitars but you can't listen to the stage themes for Storm Eagle, Flame Stag, and Gravity Beetle and not know they were clearly intended to be hardcore electric guitar shredding.

Then PSX X3 started this shift to some jazzy space sounding techno mishmash that completely changed the vibe and followed for the rest of the series.

There are definitely some bangers, X5 X vs Zero theme is one of my favorite's pieces in the series...but it was such a huge disappointment that when the tech finally allowed for CD quality music the hard rock(man) style was abandoned.