Actually, I've met most of them as well. The gathering seems to be mostly from DT.net, and I never really got into that board (too many boards, not enough time!). I mostly post on the Portnoy board since the mass exodus from the Ytsejam many years ago.
While I'm not a huge fan of DT's recent music (though I did like Train Of Thought), they always put on a great live show, and we always have a good time in NYC, so we decided this show would probably be a good time. Plus, they ended up not really playing anywhere near Baltimore this time, so it worked out.
I'd totally go see Loudness, though. I remember seeing them about a billion years ago opening up for someone else, and remember them being pretty good with a really good guitar player...
dt