It (linux) is great for battery life, and speeding up low power or older systems. starts in no time flat too. 2 to 3 seconds on a SSD in SATA II mode (ICH8m does not support SATA3).
I mainly like it because it is fully customizable. And it is not locked down like the 2 apples (OSX and Windows), which means that if there is a problem in the OS itself, you can fix it yourself. If you don't like how it does something, then you change it. If you don't like the Shell, you can change it. Basically, you are never stuck.
Windows however, you get whats in the box. Don't like how it looks, your out $30 for a program to fix it. Don't like metro, there is another $5 to fix that. Find a problem in the OS, you have to call M$, complain for a while, and maybe they fix it, maybe they don't.
OSX, it is useless. I agree there. No freedom at all. At least windows lets you choose your hardware for the most part.
yeah I can understand why Linux is good, but you have to be somewhat experimented to be able to customize it. That's why Win is pretty good for the average Joe.