Wendy is honestly more unbiased than the other one. She'll throw a compliment someone's way (even if she does drag the very same person the next day). Plus, she doesn't genuinely want to destroy someone's career unlike the other one.
They're both annoying but if I had to choose I'd go with Wendy. I'd choose pretty much anybody over Perez though. I think I'd even choose Hitler over Perez.