I know for sure at least some people are on FictFact I just don't remember who.
Apparently I created an account in 2012 but I never got to actually using it, even though I've always struggled with keeping track of all my series. So, when I saw someone recommending FictFact I thought I'd have to try it. And so I did.
It's really a great site for the purpose of keeping track of series. I'm quite ashamed that I now know I've over 120 series that I haven't actively abandoned or read to the current or last book. And there are so many more series I'd like to try.
There is little interaction between people on the site, for as far as I can tell now, but feel free to add me: My FictFact
The moderators have been very friendly and imported a lot of series that I tried to add to the database.