First off what's the current flagship Win 8, Lumia 920?
If so, I'd probably be interested in a head to head spec/price comparison between the N4 and an unlocked Lumia 920. And if we move on to software, I'd like to know how the platform is doing and how much traction its gaining. My first exposure to it has obviously been the desktop version of Win 8, and while its nice, it's still in its infancy. App support is a big factor; going from iOS > Android looks a lot smoother than transitioning to a relatively new platform, etc, etc.
Basically, I just need to know whether it's a good (better?) investment or not. I don't change phones too often, so I need carefully pick something that will still be active and attractive two years from now. In other words, I'm hoping the future holds better things for Win 8 phones that it did for Win 7 phones.