Kristen Stewart also had the media constantly in her face, which can lead to a bit of attitude. Mischa has been almost completely out of the public eye for about 10 years now, so doesn't have any of the same excuses as Kristen. Kristen also acknowledges how she is perceived and addresses that, and doesn't come off as expecting adoration, praise and accolades. That's not how I see Mischa (again, I don't know her - she may be the most lovely person ever, it's just how she comes across).
Regarding Artem vs Maks' patience, didn't Meryl say during her switch-up week how Maks is very patient and lighthearted during rehearsals?
On a different note, thinking of the switch up, I wonder how that's going to work with Nyle if they do it this year? He and Peta had a few weeks before the premiere to work on things that work for them. He won't have that with only one week with a new partner? It'll also make any group dances a bit more difficult, especially if someone other than Peta takes lead (like how Derek always took lead in choreographing them).
And finally, no Houghs this year, but also, finally, NO ALLISON!!! I'd personally rather have 37 Houghs than Allison, though her hubby is super adorable on Ellen.