I was actually involved in the testing of this site and used it during the times it was active. What I can say is, that, on paper, the idea is great. There are many great features that’s not available on the IFC.
Having said that… practically, its just a lot easier to post a topic here as there is simply a bigger audience. It just feels easier to keep everything in one place (IFC) then have a different website just for photos. Like, I never had the urge to go on the website while I was browsing the IFC, as it was just a lot easier to look at photos here.
Of course if you want to signup and continue using it that’s fine, but it won’t be too active.