I believe LEONORE (the original opera of 1806 which Beethoven later reworked as FIDELIO) is an enormously superior piece.
Agree fully 100%. IMO Fidelio is staying on the stage because its by Beethoven. It is not a strong opera, and Mahler's insertion of Leonore III makes things even worse IMO.
Reiner, what do you think of a recent suggestion that the piece which is described by Kinsky/Halm as the Introduction to Act II of the incidental music for Tarpeja (WoO2 b), actually is a prelude for Act III of Leonore?
Reports of the premiere mention such a piece, but Leonore as we know it now doesn't contain a prelude of what kind whatsoever.