The ZBrush ui at first glance does seem pretty wacky, but as with any software, if you spend enough time with it, it will make sense.
As someone that started as a traditional artist, I had a studio that appeared to outsiders as a total disaster. Maybe it was, but I knew where everything was.
Zbrush is kinda like that too.
Another nice artist's tool, (if you don't mind getting your noodle twisted around a little bit) is this one: http://polybrush.org/
I like it!