Despite the musicians involved, Red is overrated. It has a catchy riff, which they repeat throughout the album, but it becomes monotonous after a while. Red does not come close to ITCOTCK, while Wetton, Jobson and Bruford went on to make much better albums as UK. Some people like the Discipline era, but I hated it especially after the disappointment of seeing them live. The 21st Century Schizoid Band, which reunited many original members, without Robert Fripp, but with the addition of Jakko Jakszyk, were pretty good.
In the Court of the Crimson King is King Crimson's masterpiece. Everything else pales by comparison.