These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
The revelation that Cassandra turned because she was being drugged by Deathstroke. It still left a lot of holes in the story, but at least it stopped treating her as the bad guy.
There are fans (such as the Feminist Batgirl tumblr) who believe that it was ridiculous for a woman in a comic book universe (surrounded by magicians, aliens, and mad scientists, most of whom have come back from the dead at least once) to remain paralyzed by a mere bullet wound, and have been waiting for Barbara to put the cowl back on since 1988.
Supergirl: "Aren't you gonna...you know..." Batgirl: "Not unless you wanna see my bra." Supergirl: "Does it have a bat on it?"
Mary Sue: Cassandra tended to fall into this as her character went on. Even her origin story establishes her with super human powers simply by being raised as combat as her only language, a father who is supposed to be a previously unheard of super mercenary on par with Deathstroke, and near automatic approval from the previous Batgirl Barbara Gordon after a storyline of Barbara disapproving of any new Batgirls. The epithet falters, however, in light of the complete lack of standard social skills and no understanding of what constitutes appropriate in several situations (usually to comic effect). They could have been emphasized more, but they were present until the massive Face-Heel Turn removed them completely through idiotic means.
Memetic Sex God: In-Universe, the Barbara Gordon Batgirl outfit is a Memetic Sex God Outfit. Barbara mentions that Dick got a 'certain look' when she had it on, and when Cass steals it, Tim notices her in that way for the first time.