I am sorry, but I simply can't agree. The way I see it, Field's music is quite simply much less good than Chopin's. When listening to field, and his uncomplicated admittedly beautiful melody-orientated music, I associate it with people like Moscheles, Kalkbrenner, Herz, Hiller etc. All good men but not quite in Chopin's league. Furthermore while it seems like while Chopin usually uses the term Nocturne for something specific - a quiet, introspective piano piece - Field tends to use the same term for any sort of free-form piano piece. Furthermore, the very higher degree of complexity and expression with Chopin, the more spicyness one might say, makes him more subtle to me, just the way that Haydn and Mozart relates to for instance Kozeluch, Vanhal or Pleyel. But to each his own.