That's a fair assessment. Certainly the kids on SJA often seemed to know what they were doing better than the Torchwood gang did, and were less prone to screwing things up through their own actions.
Having flawed characters is a bad thing?
Not at all, but they need to still have admirable qualities as well. For some reason RTD, when populating his shows that are designed for 'adults' (as opposed to children or families), likes to create the most unappealing characters he can possibly think up. Not a single person in the first season of Torchwood was likable IMO, and the same with his recent Cucumber/Banana. All the most unpleasant people you could ever hope to meet. Having flaws is fine, but having nothing but flaws is really not. Why would I want to watch people like that?
Anyway, rant over.
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