I feel there is a little bit of a noticeable slowdown with it installed, I do like the interface and see it is obvious it is in BETA form as not all is enabled yet, the ad blocker for example. I do like the blocking page though, it is nice to have the option to decide for myself if I wish to proceed or not, decided to test it with the EICAR test file to see what would happen, feel free to checkout the block page yourself for those that decided to install it.
http://www.eicar.org/download/eicar.com
*UPDATE*
While I find the browser support and ambitions as well as apparent abilities of this program I dislike its design to run as a service at all times and not only being active when a browser is open, also the lack of choice on which browsers actively use it makes me less than happy with the installation options. The main reason however I decided to remove this is the slowdown, I tested just prior to install and right after and the loss of speed is simply too great. Ping time increased from 30ms to 531ms and not only does the lost speed become obvious during testing but it is very easily noticeable during browsing. I am hopeful the final version can address the option for which browser gets used and the speed problems, like K9 Web Protection the fact it is an always running service will not change. Great efforts and abilities but until they can resolve the dramatic performance loss in browsing the BETA tag certainly needs to remain on it, look forward to seeing the final release. (Obviously this is just what I personally experienced so many or maybe most others would not experience similar slowdowns).