once in a while, every computer needs a reboot (on the consumer level). I run with 2 laptops, desktop, 2 tablets.
1. MacMini - runs 24/7 as a media server. It is located in a well-ventilated area. I do maintenance once a month on it and reboot.
2. MacBook Pro - I close the lid (sleep mode) when I am not using it, and like the MacMini, I do maintenance once a month and reboot for sure then. When I take it out of the house, I shut it down.
3. Work laptop, Windows 7. I put it to sleep when I leave the office. SSD so no moving parts. I shut down every Friday.
4. iPad - well, sleep is the only real method. There is a hard shutdown, but it isnt needed.
5. SP2 - I shut down overnight. It is so quick to come up, it is really not noticeable. During the day, I just put it to sleep.
Computers on the consumer level, especially laptops (which, in reality, the SP2 is) are not designed to run 24/7.