This forum has gone downhill a bit in terms of quality of participants, but it's still the best trad Catholic forum I've come across. And it's been the best since it was started by Matthew after he'd been banned (or left, I forget which) by VoxClamantis. i had high hopes for the first ABLF forum, but it got really weird over there with DawnMarie and her gang.
There's been a drain of interesting members here. You used to have people like like Telesphorus, claudel, Raoul (as nutty as he was at times), columba, spouseofjesus, gladius veritatis, PilgrimageofGrace (who mainly posted on IgnisArdens), ServusSpiritus (who I haven't heard about since he abandoned the first ABLF forum), belloc, stevusmagnus, caminus, btnyc, graham, sedetrad, perejoseph, Charlemagne, Iuvenalis, partyisover221, Ethelred, Mark79, JohnGrey, and many other quality members who weren't as prolific.
There must be some change in the zeitgeist to account for the bulk of these people no longer being here. I've read Graham on SuscipeDomine say that he's put off by the proliferation of flat-earthers.
PonDeReplay was Gilgamesh over on Fisheaters. He's always been interesting to read, but he's a bit of an actor like VetusOrdo. I never thought he was a believer.
I think this forum has gone somewhat downhill as well. Everyone has their own golden age. I would guess Matthew's golden age was from 2006 until 2009 when the forum was new. But when I first discovered the forum in like 2008 or 2009 I was shocked by it and was put off because I was new to traditional Catholicism and had not digested it all yet. It was too extreme for me back then. But I came back and joined in 2010 and I thought it was the best forum I knew of. My golden age was from 2010 when I first joined until the first ABL forum started and everyone left to post there. One of the reasons I moved over to SD was because I missed a lot of the old posters here and I wanted to graze on new pastures. I miss many of the people you mentioned. Raoul76 was my favorite poster ever on this forum even though he thought I was an infiltrator, though I said once Ladislaus was my favorite poster. I also missed CM who was not on your list but he was a nutter. And I liked many of the dogmatic sedevacantist feeneyite true-saints puritan posters who would join and get banned quickly. And there are others I am sure I don't remember. The one poster I do not miss is Classicom. As far as Pon or Gilgamesh being an actor. I never knew him when he was a believer. I know he said that during his time when he claimed to be a believer the one sin he would always confess was doubting the faith. So I guess it is possible he never believed. But if he is an actor he is a good one because he fooled me as I think he is genuine, though of course you may be right. I like his style and his interests in literature art music vegetarianism Jansenism and the Church Fathers.
As far as the other forums go I did not know Angelqueen very well but I got upset when someone there was trying to argue that Jews did not need to convert to be saved, I never posted on Fisheaters or even lurked there, and know nothing of Ignis Ardens, and thought SD was alright though not as good as I remember Cathinfo during the golden age. I liked ABL 1 and was sad when it disappeared, but was not happy with its replacements. I never followed the Pfeifferite forums. And As far as Mith's forums go, I was not a big fan of them though I did post on the current one. Strangely enough even though they are sedevacantist I thought it was more liberal than Cathinfo, not less, which seems strange because of its sedevacantism, but it was an acceptable forum except for the fact that there is very little traffic. The reason I stopped posting there was because I got into an argument with one of the sedevacantists and she said "good riddance!" to me and I thought that was my cue to go so I went and stop posting there though I do check in sometime.
So I miss many of the old faces and I have been here a long time. Eight years. I hear Eamon Shea is married to a beautiful woman now. I don't know about the rest of them. I wish them all well, especially Spouse of Jesus.
I don't agree with Greg a lot, though I do enjoy him. He is a guilty pleasure. It is a sign of the relative liberalism of SD that he is on the right of that forum. I just got upset at him today and kind of insulted him on a thread on SD.