Aside from Erron, Cassie's arguably the most execution-heavy of the higher-tier characters. Even though she's got great neutral tools, you still need a lot of practice to be able to get the timing down on her combos, mainly in the Digital Soldier variation, and even then, she's not getting as much damage off of combos as other characters, and the damage that she does get, she needs to work to get. Like I posted yesterday in her variations threads, that's one area where her Yaas Queen excels since its easier to confirm a combo off of her AMPed Energy Burst than the AMPed Kneecappin, even though Kneecappin is still the superior move.