My husband either does as you described, or if he wakes up before the alarm, jumps on the computer and invariably loses track of time... after a while I look at the clock, 'Shouldn't you get going?'
'Shiiiiiit,' mad rush, putting on pants as he hops down the hallway. No breakfast, and he'll grab the toothbrush for use while driving.
He also is never late... actually hates to be late. Doesn't like making people wait for him.
If I have to get up to an alarm clock, I need about 10 mins. (No shower, that would have been done the night before. Yes sometimes I can plan). But if I wake up early, I will get completely ready so I can just relax until I have to leave.