Marlin does not understand repetier binary protocol.
In communication settings you can test communication speed for your board. Speed varies between 150 and 1000 lines per second. Also depends on how much time firmware needs to parse of course. You can test there also non ping pong modes and see the speed difference for long and short commands.
I had a closer look and no wunderstand how meatpack works. It compresses 15 important chars (0-9, ., G, X, \n) and count on them being more then 50% of chars in line to get compression of max. 50%. For move commands this is true and since they are the majority of commands it works good. Will try to implement it, should be possible the way we work. But I also expect it to have the best effect with non ping pong mode as it is the only way to send more commands per package delay. Also you should active line numbers for ok to allow Repetier-Server to detect lost "ok" so it never losses the benefit of parallel commands and also activate "wait" if you are already at config_adv.h.
