I do hope to see these performance improvements folks are talking about, and am heartened that this Cortana thing can be turned off. However, some of my first experiences with Edge just now were giving ~20 second delays between letters typed into an input field.
I am not a great fan of MS's philosophy, nor, technology, but, like I said, feel relatively stuck/trapped with it (FOR NOW). Fortunately, the 10 OS seems fairly well performing and usable thus far, and I have already seen one improvement that has completely justified the switch. The infuriating behavior I put up with for a couple of years where edge swipes would continually send me to that worthless Apps palette seem to have finally gone away. I had found ways to turn that off at times (as well as the maddening edge window maximization), but they always managed to turn themselves back on again. So now, I guess, that palette is gone, which certainly seems to be the best option.
Just heartened to see a general trend of MS chastening over time. I believe in that - "the bigger they come...", "snake eating it's tail", etc. It's been mainly the open source movement / Linux which has done it. Even if the average Joe can't appreciate Linux's quality, MS can. "Ask not for whom the bell tolls...".