Chopin's Nocturne Op. 48 No. 1 follows ternary form (ABA'). The recap passage is marked "Doppio movimento", which means "twice as fast as the preceding". I was curious to what extent the pros actually follow this directive (if it is to be taken literally at all).

Methodology: I timed how long it took to play the respective sections. The melody remains almost exactly the same, modulo some minor rhythm changes, so I think it's a fair comparison. I had initially tried to tap on the beat using the "tap tempo" feature on a metronome app, but some pianists are VERY generous with the rubato, which made it hard to pin down the bpm locally.