While Batman: The Animated Series is indubitably the best batman animated series, while The New Batman Adventures comes second to it, Batman: The Brave And Bold has done a pretty decent job in continuing the Batman media franchise. While it is true that the Brave and Bold has unfortunately toned down the darker aspect of Batman, in replacement of the more old-school style along with catchy-like punchlines, it does a successful job in diversifying the episodes by introducing many different super-villains, superheroes, and variety of settings. Unlike Batman: The Animated Series, the settings change from time to time, as well as the kinds of villains Batman struggles against.
While Batman in the Brave and Bold series is certainly different from the Batman in the Animated Series, the transition is not too dramatically different. Remember that the older batman series (such as the one in 1977) that preceded the Animated Series was far less darker and serious than both the Animated Series and Brave And Bold combined. Batman in the earlier decades was far less darker and serious, and it was when the Animated Series arrived in the 90's that firmly established a standard of what an ideal batman animated series should look like. Frank Miller also helped established the standard of the darker and grimmer batman that most of us are familiar with. Batman: Brave and Bold, in my opinion, still carries a residue of the Batman from the Animated Series (the more serious type that has expresses little sense of humor, laughs a few times) while it tries to re-live and re-make the New Adventures of Batman in a more contemporary way. I believe that while Batman: Brave and Bold has failed to satisfy many fans who expected the darker Batman from the Animated Series, it has certainly succeeded in reliving the New Adventures Series in its contemporary form.