Left aside any subjective judgement (what a wonderful bunch of nice guys and girls we are!), I think there is a fundamental feature: This is an international community. Not american, not english, not european, not local but global.
People choose this forum because they're open to broader perspectives, curious to learn more about different cultures. And, of course, people who are open to learn from different cultures are less likely to indulge to the troll and flame "mine is bigger than yours" bullshite.
Of course, being an international forum, and not a local one, has its downsides. Compared to national forums (american, spanish, australian et cetera) here on DB it is sometimes harder to find much of info on spcific local issues (where to dive near Sarasota, the best set up to shoot tarpon, good dive shops in sothwestern Turkey...).
There's good and bad on DB and in all the other forums, IMHO. But then of course DB is still my favourite cause we're a wonderful bunch of truly nice guys and girls!
Since you laid out all the pros and cons so well, I'm going to take a chance and say that I feel like I'm much more a part of a community on the California forum of Spearboard.
I dive with people from that forum. I meet many new dive buddies because of my participation in that forum. I get lots of tips on local conditions on that forum. I feel like there is a group of people who share my successes and failures.
That forum is where the fight to keep conservationists from using the Marine Life Protection Act to close most of our prime spearfishing areas is being organized and coordinated. Because of the efforts of people on that forum, I have attended three meetings, up to 110 miles from my home, and spoken out during the public comment periods. Activities like that do a lot to cement relationships and promote a sense of community. I've met many divers at those meetings, people that I had previously known only through their posts. If my only source of information was DB, I would never have heard of the MLPA, and if it were not for the efforts of people in the California forum of SB, we would be getting steamrolled by the conservationists who want every thing closed. Of course I could have brought up the subject here, but there is no one to organize, so it wouldn't have helped.
I do like the more international perspective of DB, but my diving isn't much like that of people from Romania, the UK, Ireland, Spain, etc. And while I've hosted divers from other parts of the USA that I've met on Spearboard, I've yet to meet or dive with a single person as a result of meeting through DB.
Yes, Spearboard tolerates a lot more flaming and nastiness, but the two California moderators do a pretty good job of controlling that stuff in their specific forum.
DB feels pretty much Europe and Mid-East centered, with most US participation coming from the East Coast. Its nice for me as sort of an abstract thing, but I find my community on the CA forum of SB.
I don't mean this as a criticism, but just to show that DB may not meet the needs of everyone.
Now, after writing the above, it occurs to me that friends have taken personal best white sea bass, 65 and 52 pounds, each of the last two days diving from my boat, and while I posted on Spearboard and got a lot of comment, it never even occurred to me to post on DB. The guys who got the fish are not members here, so no one would know who I was talking about, and the stories wouldn't mean much to anyone here. Maybe I should post them anyway, just to fill the vacuum in our CA-West Coast forum, but the fact that I didn't even consider it before illustrates that my strongest community ties are elsewhere.
Edit- just to illustrate the sense of community I get on SB, here are the threads for those last two days. I'm not trying to poach from DB membership or get converts to SB, and it won't happen because very few Californians will read this anyway. I'm just showing how a post there gets replies from my community, people I actually know and dive with in many cases, while someone from the UK or Abu Dhabi would not have a hell of a lot of interest in these stories.
[ame="http://www.spearboard.com/showthread.php?t=83500"]50/65.7/8 @ three arch..... - Spearboard Spearfishing Community[/ame]
[ame="http://www.spearboard.com/showthread.php?t=83556"]Sometimes you just get lucky! - Spearboard Spearfishing Community[/ame]
Well hell, not that I read them again, it was my dive buddies who started those threads anyway. Its just that it was me and my boat that were part of the stories, and I could well have started similar threads here if I felt like anyone would have been interested.