XML-RPC Ping Services slowed down posting speed

– There’s a plugin which should force all the the pings to happen asynchronously.
– Don’t USE ALL THE SERVICES. You can usually get away with a handful direct just fine, and even just one or two if using aggregating services.

For example which one of these are the best?

If you looked at the bottom of that codex page, there’s a post that lists the various services:
https://www.quickonlinetips.com/archives/2005/09/one-click-multiple-blog-services-pinging

As for which is the best? Who knows. pingomatic is run by some of the WP people, but had a rough time this spring. there’s a handful of them, I’m sure if you just search around you’ll find opinions.

-d