I've wanted to do that with an old laptop and send it to be hosted at a friend's house.

The advantage I found with a laptop :

1. Only two cables, power and ethernet. Installation and removal is quick.

2. Comes bundled with keyboard and screen so no need for monitor

3. Usually very low power consumption and low heat.

4. Light, it can be stored anywhere.

So to answer your question, I'm guessing all of the above?