AMSI is for script files. The behavior blocker monitors many more file types. One cannot expect the behavior blocker to detect all of the malware alone, for a behavior blocker the Panda's one is a good one. I have tested it with samples many times and have saw it blocking many malware files after executed. I have also saw it miss some ransomware and other threats, as you can expect from a behavior blocker. It cannot detect all of the malware and if you throw many files against it, there is always the chance to miss. Not defending Panda, but it is a good antivirus. One of the innovators to use autonomous behavior analysis + pioneer in the use of cloud infrastructure for antimalware purposes. There is no such thing as "best antivirus", at least in this world. I am using Avast currently and it doesn't have a behavior blocker at all, will get one after the AVG beta.
I agree with you. After some years, I now went back to Panda to give it a new try and I have to say they improved much. I really like their idea of the collective intelligence, but it still has some room for improvement and optimisation. The signatures are ok, but already better than in the past. The behaviour blocker is indeed not bad, but what I like about the product is that you can have full control of what is going on on your computer. I'm not talking about the free version now, but in the PRO and Internet security version, if you enable the application control, you get the same effect as Avast in strong hardened mode. It will not allow any executable that is not verified or not trusted by Panda's collective intelligence and it will ask you what to do. In the internet security, you also have the data shield, which will warn you when a ransomware passed the signatures and is trying to lock your files. It won't allow it to do so until you give the permission, which of course you never want to do. You can also immidiately set it to block instead of asking and you need to configure it a bit to get full profit from it. The web blocking of Panda is excellent and it already saved me multiple times, and no, you don't need the toolbar. Also in the process monitor of Panda, you can easily see which applications are accessing internet and which pages they visit and other interesting details. So in my opinion, the free version is easily to bypass and also on default settings, but if you use the internet security, once configured and once you have enabled the components I talked about, it's really a good AV and even for advanced users, because it will let you to control it and give you detailed reports, instead of the AV itself that have full control. You even don't need to buy it, just go to the giveaway page of Panda here on MT and grab your 180 day trial which you can install again and again.