Clone wars had cool three to four episode story arcs. I don't see Rebels doing that.

Clone Wars had great none Separatists villains. Like Hondo Ohnaka, Pre Vizsla and Savage Opress. I hope Rebels expands more than just the Inquisitor and the Empire.

It's still early, but lets face it Clone Wars was way better. I think Rebels needs more characters good and bad. The Inquisitor needs to do something awful. Like kill younglings.
Only then will Rebels be as good as Clone Wars.