Everyone is different, as are regs. Adjustment on the second stage lets me set it for what I like. Another diver may want it easier or harder.iflyprops:Edit: Oh yeah--I was talking to a caver at one of the springs down here and his take on the second stage adjustments was "why would you wan't to make a reg breathe harder, you wan't it breathing as easy as possible the entirety of the dive." He was speaking of his ATX50's.