Defender Loadout

So currently my load out for my defender is a lvl 40 rare cannon, lvl 37 epic explosive cannon, lvl 10 epic flare gun. I have enough rare items to make a lvl 40 rare explosive cannon and I was wondering if there is any benefit to running two explosive cannons over one explosive, one regular. I think the damage comes out much higher running the latter since you have weapons on cooldown less. But I see top level players running dual explosive so I wasn't sure. Any advice is much appreciated.