In the coming weeks or months I intent to post some choral preludes of Max Reger's opus 67: "52 easy preludes to the most used choral melodies."
For me they are not that easy!
In "The Straube Code", a doctoral dissertation by Henrico Stewen, there are many interesting facts about Reger and the tempo his music was played in by Straube, approved by Reger himself.
It boils down to the observation, that Reger is often played too fast, based on his metronome usage.
Apart from that, I myself feel that playing this complicated music too fast prevents the listener from hearing the extraordinary harmonies Reger uses, so I try to execute a more relaxed tempo.