Op. 126 numbers 3 and 6 are marked andante in 3/8. My understanding is that classical period 3/8 should be counted in one, and that the tempo indication always refers to the basic pulse. That would give us something like 180-200 quavers to the minute, which sounds impossibly fast (especially with the demisemiquavers in number 3).
So what do the HIP enthusiasts say about these? Is there any serious argument for considering such fast tempos? Before saying "of course not, it sounds horrible" let's remember Norrington's recording of the Ninth, or Andras Schiff's first movement of Op. 27/2 - not to everyone's taste (certainly not mine) but they do have considered arguments to justify their unusual tempos.