So yeah, Malwarebytes is a good thing to use in pair with Antiviruses. Separately, it's taking care just of malware.
Have been using Norton Internet Security suite for 3 last years - can't complain about it (well, maybe only about their Vault which, quite frankly, sucks).
What exactly do you think
malware is? For the last time malware includes virues, spyware, adware, rootkits, worms, ransomware, ect. People are using the term malware as if it is one thing. However you cannot name that one thing, because malware is a category, not just one thing.
People usually get Malwarebytes in addition to their antivirus because it can pick up things that their AV will typically miss. That is why it has the compatibility statement. However, the premium version definitely offers comparable protection to just about any AV on the market.
The main difference would be the Firewall offered by most AV's as MBAM doesn't have a built in firewall in their program. They do offer it as a separate piece of software though. Also, many AV's will have features to speed up system performance and anti-phishing protection for the browsers.
This may help you decide, there is an entire article on the best of the best for 2014
http://www.pcmag.com/article2/0,2817,2372364,00.asp