Personally, i would combine the two products. It's a great combo (MB+ZAM prenium)
But if you are combining one of them with a security suite for example, such as Bitdefender IS, ZAM would be a better choice. It has great detection rates and is easy on resources, because it's mostly cloud based.
People who hate Pups would love MB(some may find it too agressive as a downside), and i find their web protection to be excellent. MB is also a more complete tool than ZAM.
ZAM on the other side has more FPs, but it's an almost essential complement to your security setup and at a very good price. 3yrs for 30 bucks, excellent
