This piece, beyond its lovely atmosphere, hides quite complex harmonies and polyphony, even if not at the level of Albeniz’s Iberia.
The choice of the tonality and tuning of G major makes possible to enlarge the range in both bass and melody direction. This lends the music more ‘air’ and allows to play all the notes and at the right pitch. Speaking of it: in this tonality, the pitch is also closer to the original one, considering that on the piano the written notes sound, respect to the guitar, one octave higher. In this way, the light gesture of this piece is better supported than by using a lower (but easier) tonality.
Some passages might be quite complicated to play, but I think the sound effect makes the effort worth it.