And looking at the version (aka user-agent) strings of publicly reachable nodes on the network.
(e.g. see the count at  https://getaddr.bitnodes.io/nodes/ )

Yeah, though FYI Luke informed me last week that I somehow managed to take out the change to the user-agent string in Bitcoin XT, presumably I made a mistake during a rebase of the rebranding change. So the actual number of XT nodes is a bit higher than counting user-agent strings would suggest.

I sort of neglected XT lately. If we go ahead with this then I'll fix things like this.