Yes Malwarebytes 3.0 is perfectly fine for protecting Win7, and it works well with windows defender. I use MB3 on my 'Email Pc' at work, and the countless times it blocked malicious links and ads, exploits and especially Ransomwares in email attachments, i don't see myself removing MB3 anytime soon. It works perfectly as advertised.
Those who say that MB3 performs poorly in AV official tests are perfectly right.
But Malwarebytes explicitly explains that MB3 is an AV replacement, but not an AV. It will eventually fail in most tests that are designed for traditional AVs. If you put some malwares in a folder, and scan it with MB3, it will fail miserably against any traditional AV. But on an infected PC,where those malwares are already active, i'm sure after a scan, it will beat any main Internet Security suite in detecting infections of any kind.
So how can you trust a product who fails traditional AV tests?The real question is,
can you trust official AV tests actually??How many times have we seen those products getting 100% detection rate, when tested by daily users and qualified testers fail? Sometimes those obtaining those 100% effectiveness certification are themselves bloatware. Why say that MB3 doesn't obtained AV certifications in independent tests, then the product is bad and useless?
I've been using Malwarebytes since it's early beginning, and i've seen it clean countless numbers of infected PCs,i doubt that it's a weak product. For years it has been used by computer technicians to cure infections. Even recommended on AV support forums when their product fail to protect their users. Of course, it's not perfect and it has bugs like many other softwares. The direction they've taken is good i think.A small, compact and agressive product, focused on being as much proactive and effective as possible, without the need of huge signature databases.