ZBrush is very intuitive once you adapt to how its setup, the canvas and navigation is actually the hardest part to overcome. I only use about 3 tools to make these concepts so it's very easy to get going. My experience with maya was also...yeah it isn't my favourite program. It's industry standard now though, it gets more perks for game development than my native modelling package 3ds Max. You can follow any easily get up to speed with ZBrush in about 3-5 days of just following beginner tutorials. Get on it!