Yes, but you have to be very careful about the slippery slope here and how you measure things. I personally find that I sleep about the same regardless of how miserable I am at work, which means I get no quality change from roughly eight hours a day. My commute doesn't change in quality either and four many people that commute is 1 hour each way. Some people will find some other numbers that are important to subtract here. In the extreme, you'll find that an extra hour a day of work but reducing the misery of your work can result in 1 good hour of free time instead of 2 mediocre hours of free time. For most people things aren't quite that extreme but it's certainly not anything resembling 15 vs 16.

Think the same. In my case, though it is "Being excited and happy for 4-5 hours a day at work". More than that and my brain is just too tired to enjoy the rest of the day. My schedule is 40h/week, though, but I'm still productive doing half of that.