/etc/hosts doesn't work for a lot of ads, so no matter how fast it is, it's not a complete solution unless there's a browser based (or very intelligent proxy server) on top of it.
Faster, but less comprehensive. Many web sites serve content and ads off the same domain. Personally, I like uBlock Origin in combination with uMatrix in the browser, with privoxy and dnsmasq in use system-wide.
When you need a hosts file as big as you need for good ad blocking it can get pretty slow.
I think this is the case on older Windows versions but is negligible now on most systems (and apparently fine on Linux, etc., going by replies to a similar post I made a while back)