People tend to exaggerate, too, in discussions about Torchwood's "adult/mature" content. They didn't constantly curse or have a lot of sex or act juvenile all of the time. Jack and Ianto were hardly more in-your-face with the sexual content than other pairings (uh, Owen and Diane!...and not to mention Starz "home-of-Spartacus" Torchwood), but they're usually brought up as being excessive. What I didn't need to see was naked Rhys...or Johnny. LOL
Yeah, I wouldn't think S3 was OK for kids...even disregarding that last bit.
As a viewer of New Who I was quite interested in watching an "adult" spin-off when I heard it would be available; however, it did seem a bit odd that they only seemed worried about kids watching if The Doctor crossed over and even offered a pre-watershed version. Whatever, TPTB.