For stories on sci-fi, you specify age restrictions for the story, so the author specifies the appropriate ages (for readers) and the readers are expected to follow the guidelines. (I'm not sure whether Lazeez restricts contents based on age or not.)
Thus you can include either X or R-rated stories, but you can also post the 'cleaned up' versions if you think more readers would appreciate those versions.
In terms of readers, the site is MUCH smaller, and much of it's contents are 'out-of-copyright protection' content from the 50s and 60s. As a result, they appreciate the better content, but you won't get as many readers and the scores take a longer time to be 'adjusted' downward. :(
As an alternative, I often either post to FS and Sci-Fi first, or at least provide a few chapters advance on those sites in order to promote the sites.