How easy is it to temporarily switch it off if a site is broken? Like if they have some crucial JS/CSS served from a blocked domain? I also wonder this with the hosts file approach. Is that kind of flexibility you give up for speed?
This is a slight issue, we are looking at ways to make this easier. The reality on the hosts file approach we think is that we can be far more dynamic and help protect users from bad domains as well, but time will tell.