I also use a Magic Trackpad instead of a mouse at work as a dev. I also do music production exclusively with my Macbook's trackpad. I'm definitely more comfortable with it than a mouse for my normal work habits.. and I was able to beat people online in Starcraft pretty handily with a trackpad. I don't doubt that I couldn't become more precise with a mouse over time, but I really prefer scrolling and gestures to what's available on a mouse.