I used CFW for several years. Good protection and fairly straightforward to use. Unfortunately each clean install of a new version caused more and more problems until, despite following Chiron's clean install guide (link below) to the letter, it would not install and caused multiple BSODs and a lot of time and effort to get things up and running again. So I was forced to go to another product.
And it is this clean install issue which is the problem with CFW, CIS etc.Who in their right mind wants to do this every time, especially when, even if you follow it to the letter, there's still a good chance you will have problems, as I did?
Most Effective Way to Reinstall/Update CIS to Avoid/Fix Problems - Install / Setup / Configuration Help - CIS
Even if things go as planned, it is still a ridiculously complex and time consuming procedure, and if it goes wrong, as I found, it can cause a lot of grief.
If you are already using Comodo and are happy with it, fine. If you have never used Comodo and are thinking of using it, my advice would be don't. Quite simply, it is far more trouble than it is worth, especially when you try to install a new version.