Another point to consider is whether you are comfortable having your system connected to the outside all of the time. For many, it does not matter. I have a good firewall appliance, and some special configurations, to keep hackers out. But, as a last line of defense, I also shut my router down when I am not using it. I also have my firewall open in the background when I am connected. It lets me see any foreign connection attempts.
This may seem a bit 'overboard', even bordering on paranoia. But, if someone can get into my system, they can gain access to my company's computers. So, if security is not an issue for you, then remaining on-line is no more than a personal preference. On the other hand, if you need to be security aware, then make sure you have precautions set in place.