I do feel better when arriving at work by bike rather than by car, even though going by bike involves a lot of--showering, changing, making breakfast, drying clothes, etc., where as driving there doesn't involved any of this. But it might just be that I find comfort in the routine.

Riding affects my punctuality? No, not at all. In fact, the length of my commute by bike varies very little. Wind and choice of bike/tires is the biggest determinant, and it's completely predictable. I often give my wife an ETA for the homeward journey and usually right on.