In two places in the help file, we recommend you use Multirider over Coaching CS, and we give two reasons why.
The second reason listed, in both entries:
"The ErgVideo is automatically synchronized from the Play button. Coaching Software requires you to press the CompuTrainer's handlebar controller start button at the right moment, following a countdown. It's less convenient."
...no longer applies, and never has applied since we released. It is all synchronized correctly with the "Play and ride" button for both Coaching CS and Multirider. You can completely ignore this entry.
There is only one good reason to use MR, but it is COMPELLING, and worth the price of MR3 software:
"The AT-setting, and thus the overall intensity of the workout, can be adjusted while riding, using the + and - keys on the handlebar controller. If your ErgVideo session is too difficult or too easy, use this option to continue riding without disturbance. Coaching Software does not permit adjustment, you must restart the ride, after rebuilding the .erg file at a different level."
