1. Windows
1.1. Pros
1.1.1. Improved mobile broadband support and better instant-on and instant-off abilities
1.1.2. Really impressed with the sliding start button tiles as sliding on a touch screen mobile phone or Ipad.
1.2. Cons
1.2.1. Could not play my PC's speaker in full volume with Windows 8
1.2.2. Some of the applications on the start tile didn't close and I was forced to use "Task Manager" to close these apps
2. Mac OS X
2.1. Pros
2.1.1. It is awesome it's really fast and has amazing features.
2.1.2. The recover hd under the hood is a good idea
2.2. Cons
2.2.1. The only problem I am having is the Boot-up it is slow in booting up as compared to Snow Leopard.
2.2.2. It is unstable.
3. Ubuntu
3.1. Pros
3.1.1. A tremendous boost for productivity.
3.1.2. The technology has matured considerably.
3.2. Cons
3.2.1. This is still Linux and there is going to be times you'll be scratching your head wondering why something didn't work
3.2.2. New Ubuntu devices aren’t expected to reach the market until 2014, when Ubuntu 14.04 LTS is released