We are watching RGE to see how well semi-moderated posting works
RGE21.com switched to semi-moderated posting a few months ago, and we are monitoring it to see how well it works. Introducing a barrier to posting causes a onetime decline in volume. Whether that decline is permanent, or whether it is the start of an upward trend that would not have happened without the switch to a barrier to posting, is something we are trying to determine. It's possible that suffering a onetime decline in volume is worthwhile if it changes a flat trend into an upward trend.
The three advantages of unrestricted posting which BJ21.com currently uses is 1) Quick and easy posting. 2) Lots of interesting posts to read. 3) Ease of posting a message using a handle different from the one you normally use. The disadvantage of unrestricted posting is the volume of problem posts. We currently are addressing the disadvantage by using volunteer postbusters.
The only advantage to having a barrier to posting is you would encounter fewer objectionable posts. The only disadvantage is you would have to register every handle you wish to use. Even at its simplest, registration is cumbersome enough that some people who otherwise would have posted interesting messages will not bother getting permission to post.
We are fortunate that RGE21.com switched to the semi-moderated format, so that we can watch it in action before making the decision about whether to use it on BJ21.com.