I am still new to scuba diving so sorry if these two can not be compared. I am still learning. I understand that Scubapro does not make any over balance first stage but instead they make one to bench flow so much are that maybe even elephants can breath off it (inside joke) while other company comes out with overbalance first stages to cope with flow as you go deeper. My question I guess is which is better? I guess I am still trying to understand them. I brought a hollis overbalance first stage which I am sure will always supply plenty of air for me 100feet plus under water but would a MK25 still out perform it?