Uh blurry apps include all the Metro stuff, IE/Sparta, etc. It's because MS is abandoning pixel snapping in lieu of "more accurate" subpixel positioning. This approach only works well on high DPI or large fonts. It sucks compared to normal ClearType at smaller (<13 pt) sizes.
Users are gonna be hard pressed to list the advantages of 20 over 7. Console windows suck less. Start menu is back. Task manager is better. Lots of under-the-hood stuff, sure. But day to day? I've been using Win10 for months and can't think of anything. (Virtual desktops, maybe... Their implementation seems clunky compared to others I've used.)
Unless you're into metro apps and like the junk ridden store, what's the killer app? What's the huge win in upgrading?