If things average out on week (or even month) level, then I think you are absolutely right. So far they pretty much have for me. In full disclosure, my job is effectively lead developer right now, and I am officially "manager" for only one junior level programmer. Who's been awesome so far, and my push with her has been mostly making sure she leaves on time as I worry she's working too hard.

Yeah, I'm talking about the month or even multiple month level. Also, our company's culture is similar to your last statement - get your work done, and please don't kill yourself. Work/life balance is important to us.

I'm in a similar situation as you, one of an upper echelon of devs and while nothing is ever official sometimes increasingly there are people "under" me on any given project. So because of that, the tasks that I'm holding in my mind and have deadlines for tend to be longer running - not the typical 4 hour sprint ticket.

If I was fresh out of college and simply pulling stickies off the queue I'd likely have a different take on things. In those situations it's literally just a matter of doing something and moving on to the next something. My personal experience these days is different, it takes a little bit to shift gears and move on to the next thing, it's not as simple as simply grabbing a sticky.

For me as a developer, the difference is huge, for the negative. An unplanned day of "slacking off" is a small gain, and they absolutely don't make up for the days when I feel like I'm doing nothing else but work, eat and sleep.