Just my 2 cents, but the vkb on the n950 is really good. Coming from the n900 where I don't think i've ever used the vkb more than twice in over 2 years, I find myself rarely opening the real keyboard on the n950. I think the main drawback of the vkb is the screen real-estate, but even that is handled quite well (compared to Symbian^3, where the vkb is ok, but it takes so much space you can't see what you're writing).
In my opinion, unless you're writing an essay or coding on there, the vkb seems good enough to justify the width and weight loss that the N9 will bring compared to the N950.