I too see it as IRC but with eye candy and good live DJ's ... what's not to like about it? I've never understood the whole anti SL 'sadville' thing *shrug*
When I am in IRC I usually talk about the same things and write about myself. In SL it is very tempting to talk more about the fictional or virtual life of your AV, Artwork in SL and the people who created it. In fact, I hated it when people asked me about RL! But there were others that used it like IRC, some used their land like homepages... And yes, there is the disco-folks too. Very diverse community.
But the place is pretty much deserted now. Many ambitious guys couldn´t afford the rent and so the best islands vanished and took part of the crowd with them.
Some pople who are much into building things joined the "open simulator" project, which uses the same kind of servers with a different twist and far less costly - but you have to be willing to invest some time and are talking to a much smaller audience.
