CanadianMaestro
Headphoneus Supremus
When it comes to the Missa Solemnis I steer away from Karajan, my recommendations are Klemperer for those who seek for grandeur
or Herreweghe for the hipsters
I have both of the above, they are superb. The Karajan is mainly for the vocal team of Wunderlich, Ludwig, et al., which was wonderful.
It's a superior piece, better than Mozzie's Requiem. But gets far less fame than the Requiem. Go figure.