I am waiting for my own X1 to arrive (i7-5600, 512 SSD, non-touch 2560x1440 panel) and I did not resist reading your review. Thanks.
I wonder what changes in battery life when the non-touch IPS panel is considered. Battery life aside, what about brightness and contrast for the non-touch? And what about the difference in weight?
As kitarek points out in her/his comment, the 512GB SSD should boost the i/o speed, in principle by a 3x factor. In turn, this PCIe connected SSD should also allow ultrafast swapping when the RAM is low, thus improving a huge range of other computational/performance features at the same time.
As a personal note, I am going back to Lenovo after a 1.5 years with a Dell XPS 15. Yes, an amazing machine on paper, but full of little problems and - on the top of that - Dell offers one of the worst technical support ever. Btw, before Dell, with my Lenovo laptops neither I nor my colleagues had to call the technical support, never.