Nice article. One thing I want to know is there any difference in display light intensity between hp 450 and 250. I have both laptops, but 250 have little bit darker screen. Is that a factory mistake, or something else?
As for the screen, you took the ProBook 470 and calibrated it - the blue cast was gone. There's no reason why it would not work on this one too. The uncalibrated grayscale charts of both 450 and 470 are pretty much the same, with clearly visible bluish readings.
I am quite amazed that you haven't mentioned the rubber lid, this is definitely something that would attract some costumers, while drive away others... It is definitely the biggest change of the exterior since the previous generation (4540s). To be sincere, that's all that's changed since the last version! No Haswell inside or other "internal" advancements...
Another thing: battery running time of barely more that 3 hours is considered at least mediocre, not to be crude. Even you at notebookcheck have considered battery running time of 4 hrs as mediocre or average... This is horrible!
15.6-inch 16:9 screen with a resolution of 1366x768 pixels? It's a shame, tablets and even phones have better! Who wants to buy such, especially for business? They are stubbornly producing "crapbooks" and are surprised about decreasing market! Please, please let me have an option to buy a laptop with 16:10 or 4:3 screen and good screen resolution!