When you say you're more inclined to a "slower tempo" what is that tempo? Daydreaming is good; nodding off to sleep because the tempo is too slow is not good.
Remember that the work is marked
Andantino (slightly faster than
andante [1]to which Debussy adds
sans lenteur. I think that Debussy is trying to assure that the performer not play this too slowly. It has to move with a gentle forward motion; I'd be inclined even to say that it should be felt as two in a bar rather than four. My tempo would not be any slower than MM=100 - quarter note.
I've listened to a few ponderously slow versions on You Tube - amateurs, all - and to my taste they give no sense of movement or direction to the piece, and they ignore Debussy's tempo indications. The great Aldo Ciccolini's tempo is exemplary, a little slower than mine, actually, but certainly an admirable one. Only a "professional" with the control that he has can take it this slowly and still make it both move and sing.
Reverie, Ciccolini [1] from the Virginia Tech Multimedia Music Dictionary :
"A moderate tempo marking slightly faster than Andante and slower than Moderato. Although Andantino is the diminutive form of Andante and should designate a slower tempo than Andante, it actually came to mean the opposite. Prior to the late 18th century, Andantino may have actually meant slower than Andante."
Regards,
