I agree that the flexibility goes both ways. In your situation do you feel that the trip home at the end of your last day of work is work time or vacation time?
that's still my vacation time. *I* get to choose whether to perform work tasks or not. (usually I at least start clearing out emails if the laundry and other 'house' stuff i need to catch up on are completed...) my vacation ends when the 'out of office' message is shut off.
in my experience that trip home has given me some of the best memories of my life...and the inbox will still be full.
if i'm working for someone who doesn't understand that, then i'm not in the right place...(fortunately i am in the right place, and it is a blessing).