No clue as to the reason for spitting coolant with the 160 over the 180 but I will tell you that if the engien wants to run at say 190 niether stat will stop it. It will run the temp it wants to run if that temp is above the stat rating.
The burping problem is the reason vehicle manufacturers instituted the coolant recovery systems on the vehicles. It was very common in the days prior to the advent of the recovery systems.