I have recently owned an Ego7, DM7 and Angel 1.
The angel, i can't honestly remember the last time I broke a ball, but I have only ever really used decent paint (draxxus blaze) and I believe it is as much to do with that as anything.The only time i had trouble was when my loader went down once mysteriously and I borrowed a pulse for the day, which gave me nothing but soup and spray from the same marker, but a v35 halo never gave any trouble at all.
the ego and dm didn't seem to break any more or less than each other. there are too many variables. you would need to use the same air bottle, same loader, fresh batteries and several markers along with the same batch of paint to give you any conclusive results.