Regex is a powerful and effective way of blocking,but can also be too powerful as it can block false positives easily as well,but it cuts down on the need for massive block list as well. So there are pros and cons.Interesting benchmark, but it does only measure the difference between two block modes. As you mentioned, it does not measure the impact of DNS filtering, would it be local or remote.
The latency to our servers would be the major factor impacting the performance. As most DNS queries are performed in parallel, the performance to your DNS resolver, with local or remote filtering, will have the biggest impact on performance. What you don’t want, is filtering slowing down your DNS query latency. That is why with carefully select the blocklists we propose and avoid impossible to optimize matching methods like regex.