There are a couple of current threads in this forum on AV testing.
One thing that the testing organizations (and tests) have in common is that none of them tested mbam. Even though they tested multiple other free products.
It seems to me that this is a common occurance.
How can you have confidence in a product that (essentially) never gets tested/rated?
How do you really know if it's effective?
Is MalwareBytes not considered a real player in the AV industry?
joen - I'm not sure about the full version of Malwarebytes', but I still think the Free version is really good for an on-demand scanner. I don't have NAV but I've had NIS for several years and Malwarebytes' and SUPERAntiSpyware both play nice with Nortons. They work very well if you want a second or third opinion.
my only comment would be that the figures don't lie but the liars sure can figure 
I'm sure that somewhere out there there is a test configuration that will score anything as the best.
I'm more comfortable with the years of experience and knowledge base of the folks that frequent here than I am with the results of a 'test' published '[add a name that suits you]"
End of rant