Best is overwhelmingly the time saved and the best use of time.
So not only the time saved in not having to travel, but it is the usefulness of time that you can take out of your morning for 15mins and just work 15mins longer at the end or start of the day.
So, for example, being able to hang washing out at 10am on a sunny day, rather than coming home to a wet load in the machine at 6pm. That 15mins is still worked, just by starting or finishing earlier or later.
Same with things like arranging to have your boiler serviced or piano tuned or carpet fitted or whatever, so you can let the chap in, make him a cuppa and crack on with your work without having to take a day off to wait in for them.
Or at lunch, instead of sitting in staffroom for a lunchbreak, chatting, you can be prepping your evening meal.
When you empty the dishwasher when waiting for the kettle to boil, it is your dishwasher that is then empty, and not the one in the staff kitchen.
It is also nice to be able to pull on some joggers and put feet in slippers when you get up and not needing to dress up a bit more on the days at home.
Nice to be able to listen to music of own choice, or sit in silence, as you prefer.
Nice to be able to focus and not be interrupted by people around you.
Just flexibility of time generally - I'm happy, when on a roll, to "stay late" in my own spare bedroom to finish something off, knowing that banks me time for when I might want to take a short break or start late or finish early another day without it all being too formal.
Downside is paying for a certain amount of heating / electricity, but then I save in not using petrol and wear and tear on the car.