Torn between MBA 13" & Surface Pro 2

I'm looking to replace my Toshiba Satellite 14" touchscreen laptop with an Ivy Bridge i5 AND my Surface RT with one device. I need something that'll be a reliable workhorse at home, and an easy thing to grab 'n go. I need power and portability. My laptop still works great, and my Surface is great for at-school use with it's portability and battery life. I've been really considering a Macbook Air 13"because it would be ideal to do the jobs of both, but with the release of the Surface 2 Pro approaching I figured that it could do just the same.

The major trade offs from a hardware perspective are pretty minute. With the MBA, you get the traditional laptop form factor that will rest on your lap naturally (my favorite way to use any device). With the SP2, the second angle of the hinge is suppose to enhance the "lap experience" and make it more "lapable," but I'm sure it would still be second to any traditional laptop, not just the Macbook. But what you lose in "lapability," you gain in a touchscreen with an active digitizing display. Sure, the Air has double the battery life, but 6-7 hours is definitely manageable. This time last year it would be considered great. Another thing the Surface has to offer is the dock for the desktop experience, but I'm sure a similar rig could be setup for the MBA.

So tell me, Core, what do you think is the better device?