Weasyl does have its fair share of problems as well. From what I have heard they have problems with the structure of their staff and there are just not a lot of people posting there.
Yesterday I re-watched everyone there who I watch on FA. Out of roughly 1300 people on my watchlist I found about 400. And a big chunk of the accounts that I did find were inactive.
As for activity, yesterday they had a total of 10.401 users visiting the site. FA has over 10.000 users online at any given time.
At the moment things don't seem to be looking too hot for them... If FA happens to go under (for what ever reason) people will switch there. The other alternatives would be SoFurry and Inkbunny... But no one ever mentions SF when this topic comes up and all the pedos have already moved to IB.
Lately they've cleaned up staff issues from what I've heard. (And it's not like FA staff structure is any better...) As for the "not a lot of people" posting there, I've found there's a tight knit groups of people there. I suppose it's all where you're looking. At this point the convenience of FA isn't even enough to keep me around for long.