I would say it has a calming effect throughout the day, because when you sit you practice the mental activity of bringing your attention to the present moment. It's like building a muscle; when the muscle is stronger you can use it throughout the day. At first it's very hard to control your attention, but with practice you get better at it, and will start to notice your mind going off into repetitive thought patterns sooner.

The above has been my experience also. It's sorta like I discovered how to interface with my mind? I can kinda be like... yo, what do you think about this? listen for a bit to what is "said" and then move on.