I have just registered today,they allow free members submit one/day.I cannot say now whether fake or true.
As of my experience you can get good back link through the social bookmarking and it help's getting a good traffic to the website. There are lot's of social bookmarking website's out there but i would prefer Facebook , twitter, Digg, stumbleupon and reddit.
You can check your report after submitting your site. I don't think they are fake, i can see my live links on report. But they don't have high quality bookmarking sites on their list.