There is no doubt in my mind that ZBrush is immensely capable - so is Adobe Illustrator and although I am completely at home in PS, Illustrator continues to give me fits. Both are great software, it’s me who “gets” one and not the other. I would cheerfully buy ZBrush this minute if I felt that I could “get” it. Absent a trial version, even for pay a la Modo, I am very reluctant to simply buy ZBrush and then see if we can work together.
I would appreciate hearing from ZBrush users on this subject and it would help if you listed any other modelling or imaging software that you used, or are using.