I have had all kinds of reactions, from very negative (especially at several old school lds's, who are quite often threatened by the entire internet world lurking just outside their front door, ready to devour them), to "OH, what is your user name?".
Some divers have never heard of SB, but these days that is getting more rare. To them I suggest the board as a research and contact source.
Some diver, even in my own local club, seem to want to stay aloof, and to them I act as a conduit, bringing stories and ideas into meetings, and listing SB as the source.
At the lds, they shudder when I mention SB, but that has never caused me to stop, as I see any ability to network as advantageous to myself, and it's their loss if they choose to ignore the opportunities that networking could offer them too.
I have heard complaints that SB is unfriendly, egotistic, antagonistic, and full of half baked know it all's. My replay to that is, yes, sometimes it has those folks, but it has several hundred thousand others too, and it is up to you to chose who you want to discuss things with, or be impacted by.