I’ve run all three setups at one time or another. I have a dual front, single rear configuration on my Merckx, and double front and rear on my Raleigh; both are Campagnolo setups, and the mixed braking system is a common and deliberate option with many of their groups.
My experience is that a pair of dual pivot brakes provides ample stopping power with good modulation. The mixed system is somewhat less powerful, with better modulation in wet conditions.
Either combination will stop you with more urgency than the single pivot brakes on 80s era brakes with greater control.