These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Awesome Music: Plenty of it— not surprising given the members' virtuosity and the sheer amount of Epic Rocking they do. Just about every fan will put "21st Century Schizoid Man," "Fracture," and "Starless" at the top of the list.
The Lizard lineup in "Bolero: The Peacock's Tale" where they reprise the verse section of the moody "Prince Rupert Awakes" as a Rat Pack-styled swing.
Happy With What You Have To Be Happy With EP includes a bonus track at the end of the album which features almost 4 minutes of (sometimes ridiculous) improvisations, and a lot of random banter between the group.
Ending Fatigue: "Moonchild" from In the Court of the Crimson King suffers from this big time, with ten minutes of ambient improvisation that goes nowhere. It's almost universally considered the low point of their otherwise beloved debut album.
"Starless" is undoubtedly a beautiful song, but damn if that instrumental section isn't long (about 8 minutes after the lyrical part has ended).
Peter Sinfield may actually be a case of World of Symbolism: he has an entire site dedicated to explaining the elaborate, obscure tapestry of historical, religious, and mythological references in his lyrics. Doesn't make the lyrics themselves any less mind-boggling, though.
Ur Example: Heavier moments make them overlap with Progressive Metal, especially on the album Red. "21st Century Schizoid Man" and "Larks' Tongues in Aspic (Part Two)" are also good examples of this, and are frequently covered by progressive metal groups.