I used Weasyl once but abandoned it eventually. Wasn't a fan.

Obviously I'm no artist and can't commission anything ever. But I do very much prefer Weasyl over FA. I at least tend to check in there more often than FA, that's for sure.

I have no idea about FurryNetwork. It doesn't really seem like a Faespoak clone to me, but then again, I never use Spymag. ¯\_(ツ)_/¯

I enjoy weasyl

I am on both, FurryNetwork is pretty okay, things have been updated a lot, I still am not a fan of the square side by side browsing and stuff, but it works and seems okay

I don't think anyone really uses em nope. Weasyl tried but didn't seem to catch on.

I see some artists doing better on other sites then they do here. I think it's because there less competition.

I'm on Weasyl and FN. Weasyl has fewer options than FA but is a bit easier to use, imo. For example if you're using markup code in a journal , it has a preview so you can immediately tell if you entered it correctly. And the Collection feature is nice to avoid dups.
FN I haven't used as much, I think the UI is a bit clunky, and mainly created it to snag the username for MaineFurs (we had an issue with an unpleasant person creating accounts).
I know there's something (postybird?) a lot of artists use which makes it easier to upload pieces to multiple sites like FA, Weasyl, etc.

I've accounts on all the sites, but never used any of them besides FA.
I'm just used to how things work here and didn't find those other sites intuitive, or useful for me as a porn-watcher-and-sometimes-commissioner. FA had all I needed, so I really never checked back on the other sites.