As far as matchups go, Elvenshadow is right. Millia > Faust while Faust > I-no in comparison, mainly due to Millia being more mobile than I-no (has a ground dash, 2 air dashes, moves that move her quickly across the screen) and a more solid way to get in. I-no's note and HCL are great for setting up lockdown/knockdowns but Faust is great at dodging both. The same can be said for Millia's hairpin at times, but adding that to her mobility, she gets more chances to get in for free and mixup.
Defense wise, I'd pick I-no over Millia. Better/longer backdash invul, one move that is semi-reversalable (wakeup VCL), better wakeup supers).
Now, cos it's Koichi...maybe he SHOULD have picked I-no just cos his I-no is so good...maybe not. If you're going by numbers though, Millia is the right choice.