I gave it a 4/5 only because some critical updates are late in arriving or becoming available for the free version. Captcha was a pay only feature for a while. Also, I know the 2.5 version is coming later this month, but ...
Having said that, the 1.7 version does appear to be stable on 2.5, so I'm moving forward with that in my development/test environment until the official 2.5 stable version of CB is released.
Overall, CB is great extension and highly recommended. If I was doing more professional projects that create revenue streams, I would probably do one of the pay subscriptions.
The extension also integrates seamlessly with CB. Upgrading has also been a breeze. Thanks!
There were a few problems getting everything working, but that was my fault. I would highly recommend reading the documentation and creating an upgrade plan before getting started.
The first issue is to make sure that if you're coming 1.5.x that you upgrade to 1.5.25. Second, if you want automatically migrate extensions, make sure the currently installed versions are 2.5 compatible. CB and Kunena are good examples of extensions that can be installed in 1.5.25 and automatically migrated to the new 2.5 site. Interestingly, I thought CB would have issues, but the 1.7 version core functionality appears to be working correctly in the new 2.5 site. In other cases, you might have to go to 1.7 first since it seems that many extensions are 1.7/2.5 compatible.
I still have a lot of work to do, but this extension definitely made my life a lot easier. Thanks and great job!