I did a poll and nearly 30% of the people who voted said they used Sync! It's stayed around that percent the whole time too!
EDIT: Here is the poll I forgot to put this here like five times lol https://strawpoll.com/wby5A21R1yA
from someone that used Connect before Sync was available: it works but feels like someone's hobby. lots of issues and quirks to work around. Sync is absolutely perfect and I wouldn't be using lemmy without it.