I can't speak for all women, but the ones I've known sure as shit talk about that stuff. They just have more tact than to do it in front of (straight) guys. Once they know you're gay, though, you get invited into those conversations.
Gay guys probably talk more often about dicks, I'll grant you that, but it's probably for the same reason that straight women talk about vagina more than gay guys do. That, and because men have more freedom, socially, to talk about some aspects of sex than women do - especially once you get over the "does talking about this infer to anyone that I could be gay" bullshit.