I'm sort of confused. Last week, Dr. N commented on my playing of the Chopin Etude Op. 25, No. 7 (C-sharp minor). She recommended that I not use as much rubato in the piece or else the piece will lose 'its momemtum'. However, I remember a couple months ago where she raved about Pollini's recording of the Etudes. But listening to the Pollini recording (of this piece), Pollini probably uses more rubato although he builds momentum by driving forward (with tempo and rhythm) in certain sections of the piece. I know my instructor has a penchant for steady, metronomic rhythms for a piece, but I think I'm gonna have to respectfully disagree with my instructor on this aspect, only because this is Chopin. If there's a composer who demands rubato (at least a moderate amount), it's him.