His strongest renditions are that of Bruckner. Unlike other conductors, such as the classical "rockstar" Karajan, he would approach the symphonies in a glacial pace, often ending up 30 minutes longer than a typical rendition. However, this is where his craftmanship shines, with precise and transcendent harmonics that no other rendition can achieve. His 8th symphony is an experience one can not miss in his lifetime.
It's actually my first time hearing his rendition of Bolero, but I've already noticed the mark of the conductor: taking time to make sure each phrase is accurately pronounced. I'll have to re-listen for more observations.
In addition, Celibidache was not a perfect person. He was later known for his sexism, refusing to hire a qualified trombonist as first trombone after she passed a screen-blinded audition. [1]
[1] https://www.timescolonist.com/entertainment/music/female-tro...