I got a MacBook Pro Retina a few months ago and I'm really happy with it. However, since I do a lot of work in different environments/OSes, I make heavy use of VMware to have them with me when I'm on the road.
The MBPr has a great battery life - as long as integrated graphics are being used. Unfortunately as soon as I launch VMware, the MacBook switches to discrete graphics and battery life is effectively halved.
I noticed that after installing gfxCardStatus, and now I'm wondering if there is a way to force the integrated graphics being used all of the time, so I can enjoy maximum battery life.