We don't have actual specs for Scorpio yet, just the GPU target. But I expect the power difference to be notable between Scorpio and Pro regardless.
How it'll play out will be interesting to see because Scorpio will still be tied to the XB1 base. I largely expect them to be similar to Sony in what they allow or don't allow (FPS differentials for MP games forbidden for example, so no 60FPS for a Souls game). It'll have tons more native 4K games I think as a result (or closer resolution depending on the game). CPU is also unknown but it's far more likely then Pro to get a boost to 60 FPS in certain games, but again, depends on the title and it's MP component on the base XB1.
Because of this, I'm not sure how pronounced the actual graphical difference between Pro mode and Scorpio mode will be, but I think it'll largely come down to a matter of image quality first and foremost.
As for sales, no one has really put any sort of convincing reason forward why MS with Scorpio will suddenly take make marketshare or become successfull or flip the table on Sony.
Saying power, power, power a bunch of times isn't going to summon a genie and make it happen.