Hi all. I generate* the packages that make up those UbuntuCore relays and bridges you hear about some time in here.
I intended it to be a low-friction way normal joes can help Tor. There have been a good number of volunteers.
The automatic-update system of Snap means the security update of a few days ago gives some population info through download stats.
About 2200+ machines updated to last week's release. Almost all are amd64, though a few percent are i386 or armhf. I don't know of any arm64 yet. They're mostly desktops and servers. I see several new downloads every day.
Judging from the new Atlas, about 800 are have checked in to try to join the consensus, and a little more than 100 are active at any time.
Some working details: The package has a kill-switch so that it no longer starts after a few months of staleness (if I'm ever hit by a bus). At first launch, Tor creates a key and the last two bits of the key determines the role of the instance, with a 1/4 chance of becoming a obfs4 bridge. The default bandwidth limit is a modest 4 megabits per second. Also by default, it tries to punch holes in NAT to make itself available for incoming connections, but I don't have a lot of confidence that is often successful.
I remain on this list and am always happy to answer questions or suggestions.
* http://bazaar.launchpad.net/~privacy-squad/+junk/tor-middle-relay-snap/files