This season is more bitchy, which I don't really like. That's why I like when RuPaul says she does "Sassy" not "Bitchy". You can get your point across without verbally assaulting someone.
As far as Tyra, I don't think she's a bitch, I think she's stupid. Perhaps clinically so. I think nothing about her is calculated, because that would require thinking. She's just lucky that she has one makeup look that works, and someone who taught her how to put outfits together. I feel like if she ever has to lip-sync for her life, it will be boring as hell, and she will sashay away.
My fav, Jessica. She's a great performer, and she gets the job done without getting involved in all the drama. I think she's the dark horse of the show.