We boated a mixed 4- with an Olympian, a M4x, and a W2x today. Everybody came off the water happy.
4- and 4x did not get to race - but the 4x was competitive understroking the 4- by about 6 beats per minute.
Chart for the M4x - the speedcoach of the 4- did not record - thanks to NIELSEN-KELLERMAN NK's crappy XL2 firmware that stops recording when the charge gets low...