Sorry. I am not willing to take a chance when there are better options.
I have a lot of experience with Windows products and MS’ strength is on the PC.
Also, trying to “unify” the applications and the GIU is insane. Certainly, the look and feel will be the same. But the software tends to be a kludge, one size fits all.
I really hated it when Windows switched to the unified GUI. I am of the belief that if it ain’t broke don’t fix it. Linux did something similar.
I share somemof your concerns. I guess we’ll have to wait and see. In the interim, my Lumia 1520, which hasn’t gotten the Windows Phone 10 update yet, is still suiting me just fine.