[FairyKing]

IMO Izu is more consistently okay, at worst she just blends into the background, but she doesn't have many moments where she really shines. Mei on the other hand has plenty of moments where she's actively annoying, but also has more scenes where it feels like she actually adds something to the cast besides exposition.

It's a perfect demonstration of machines vs humans: a machine can consistently meet a set standard of quality, but will rarely excel beyond its baseline, while a human is a variable, with the risk of falling below what's desired but also the potential to exceed expectations.