Im not a fan. I've watched regular use suck the life and personality out of several people I was close to over the years, and I don't wish those effects on anyone.
In response to the 'a lot of successful people use it' argument, please bear in mind that a lot of hugely successful people are heroine addicts also ... Does their societal status make it OK?
In my house, anything that is illegal will not be accepted - including underage drinking. I know my kids will have exposure to these things eventually, but I'm hoping they will respect their bodies enough to not purposefully damage them.