My LBS made the decision - they had M540's in stock. I love 'em. I put 11,000 miles on my first pair before deciding my backup bike needed them - so I bought new M540's and put them on the "good bike" transferring the old pedals to the backup bike. No maintenance issues whatsoever. I keep the tension very loose, have never unintentionally unclipped but they released easily avoiding knee torque during crashes.