I've kept out of this until now, but I'll weigh in, however unsteadily.
I am/was a regular of both EG and GJ, from the time I joined HC in 2006. Most of you probably aren't aware of me, because I fly under the radar and I don't ruffle people's feathers. I try hard to make my posts informative and mostly serious, although in GJ I've been able to let loose sometimes.
I have tried to stay engaged in the forums since the January meltdown, but it's been hard, partly because of the awkward (although stable, admittedly) new forum software, and mostly because that awkwardness has resulted in a major exodus of many of the knowledgeable people we had in those forums.
The fact is that it's been almost five months since the old HC disappeared, and this new HC still feels like it's in beta, and we're the beta testers. It's hard not to feel frustrated by the slow progress. A lot of people have simply given up and are finding other solutions. Some of those alternatives, like Guitar Amp Board, are thriving in the face of HC's continuing struggles.
And to make a bit of a confession, I have hardly played my guitars at all since January. My attention has been diverted by other things -- my growing family and my writing projects, primarily -- and the problems with HC were a catalyst for that. For years, HC was a daily, often hourly obsession. I spent countless work hours in front of HC, when I should have been, well, working. This place inspired me to pick up guitars again (after many years away from them), and it continued to feed that addiction to gear and my "sound" and playing and having fun. The meltdown forced me to reevaluate my priorities. I relegated my guitar obsession to where it probably should be: a nice hobby I can spend a few hours a week at, maybe, but no more than that. So you can count me as one of the intangibles. I'm now spending less time here, because the end of the previous HC and the rebirth of a new HC have taken away that addictive quality I thrived on. And I'm afraid that may never return. I'm still here trying to see the glass as half full, but there seems to be less and less left in the glass.
I wanted to address the PG-13 issue and the "opt in" issue, but that may have to wait. In a nutshell, I think both are restrictive and not constructive. The goal should be to rebuild this community we used to have, not to stifle participation. Both of those changes do nothing to rebuild HC, IMO. They segregate rather than integrate, and I'm not convinced that's the stuff of a thriving community.