For street riding, I like to ride conservatively enough to only use the back brake + engine braking 95% of the time. I treat my front brake like an emergency brake for when I absolutely have to stop way shorter than I originally thought I would, like coming up to a light that changes unexpectedly or when someone cuts me off or whatever. I just find that if I use the weak brake gives me a lot more "oh ****" room than if I am already braking at 90% of what the bike can give me.
If I am pushing the bike as hard as it can go, then yeah I will be using the front brake mostly, but I dont try to set lap time records on the way to work (most of the time).