I never thought Chrono Cross' battles were slow or boring. At least you're actively doing something most of the time, while in FFIX, you can easily spend almost a minute idle, just watching the characters stand in the "preparing to take action" pose, being stuck in the turn queue for a long time. Then again, I was also around 15 when I played Chrono Cross, so I may have plenty of nostalgia blinding my memories there.