It's both doable, and recommended by many people.
I'm running non-staggered on my P85+ right now. In fact I'm a real heretic in that I'm even running 19" wheels on mine.
The upside is decreased tire wear due to tire rotations, as well as cheaper and easier to find rear tires, coupled with better efficiency due to smaller contact area on the rear tires.
The downside is that slightly narrower rear tires mean slightly less grip on those tires when you floor it. So I don't recommend it if you plan to race the car a lot.