Let's say that we have an hotel reservation system, and a choice between three kinds of rooms. Also, we can choose between having TV or not. (This is not the real use case, but it's a simplification to show the point). This gives:
Now, when you choose the economy room, TV is not included by default, and if you check TV there will be an extra charge. So, the initial state of "TV" is not checked.
When you choose standard room or luxury room, the TV is included by default. The initial state will be checked. However, some users prefer to uncheck it (for whatever reason).
The above layout makes easy to check if there will be or not a TV. The typical user is using this screen 20 times a day, so he will not read the label and only look at the mark.
However, the information "is this a standard decision or am i opting for the special" is somehow hidden.
The alternative would be
Now, it's much more clear when you are changing the standard. However, knowing if there will be a TV or not is more involved, you need to really read the label.
I find it difficult to choose between the 2 scenes ....
Also, may be there is another design that combines the best of the two ?
Note: This is a simplified design. The "room" part is way more complex, and I would prefer not changing it. The design changes should afect only the lower part. (The TV checkbox, that doesn't need to be a checkbox at all)