Having finally read the "offending" issue this morning, I have to say it was actually a really fun story. I do think Cassandra's quitting was extremely abrupt and ill-explained within the context of the comic. However, the rest of the story was fun. There were a few patches of spotty text (mostly in the thought boxes) but I think it's a good start for the ongoing.
Anyways, I don't think you've seen the last of Cass in this series. I think it is good to be fans of a character and follow them but I think you are letting your love of Cassandra Cain (whose entire story is kind of fucked to hell and back at the moment) overshadow what I think is going to be a really exciting new series.