Persons are different. If someone is balanced, already introverted and has no trouble living in the moment and being happy just breathing and moving then I maintain that meditation can have prolonged adverse effects outside the period of actual meditation.

If another person is extroverted, perhaps even to the point of being hyperactive, then meditation (as you described it) may help.

In general I see very little connection though between meditation and intellectual output. Many famous people who are known for taking to Buddhism did so after accomplishing their major works.

I also doubt that meditation, even if it leads to a rested mind, helps focusing in noisy environments.

[same person as above -- sorry dang!]