I have both here. I love them both. I sold my Q10 and get myself a Z30. Austriker knows the story
Then , all of a sudden after a month , I felt going back to the Q10. Sound sick, I know. Now I have them here, and I still love my Z30 slightly more. Decision time was easy. As a creative Business user, I love the bigger screen. it's better for my eyes. Emails, etc. I love the big screen. paratek antenna, 2 microphones, virtual keyboard is really awesome and it's the newer model.
I don't know. I just love the Z30. Cant tell you why. Oh, and the battery. It's just top notch.