I'm a fan of the Asus transformer too. One benefit from the keyboard having a battery that I didn't notice till I had been using it this way for a while is that I never charge the tablet directly. When it is low, I attach the keyboard and let that charge the tablet. Then when the keyboard is low I pull that off and charge it. So the tablet itself is never tied to a wall. Psychologically, the tablet feels a hair's breadth away from being a device I don't have to charge at all. The battery state is never in the way of me using it.
Ever try using classic windows interface with your bulky fingers? This is why the Touchsmart shipped with a weighted pen-sized stylus, even in models with the passive touchscreen.
How is Office with the Touchpad?
There is a benefit of having both the desktop and "Metro".
I'm going to take a look at the Atom-powered Vivo Tab that runs the full version of Windows 8 when it comes out, but I suspect that the keyboard may still be too small.
Samsung's convertible tablet is 11.6", which has already proven itself to be large enough for a full size keyboard, when its done properly.
I wish Asus, or someone else, would come out with a convertible that's as thin, light, and attractive as the Zenbook Prime, but with a screen that's 11-13" and 1080p, with an i5, 8GB of ram, a wacom digitizer, and a quality keyboard.
Office on the other hand is a production app. Not a consumption app. It's workflow fits best on the Desktop PC with a keyboard.
So when I saw the Surface I thought "yes Microsoft gets it!" Then you use windows 8 RT and realize they're about as out-of-touch as ever. Behind that nice tablet interface is the same old windows. Ever try using classic windows interface with your bulky fingers? That's exactly what you have to do with essential apps like Office or anything written > 3 months ago. It's the exact reason tablets didn't catch on in the early 2000s: windows wasn't designed for use on a touchscreen.