Well, it seems you already made your mind because your questions about Windows 10 interface and experience could be easily answered by a quick Google or YouTube search, or a visit to the Windows 10 thread.
TL/DR: It's far better and less confusing than 8 and it's full of changes that improve the desktop experience over 7, like virtual desktops, improved window snapping, much faster search, scroll wheel works without need to click things first (secret game changer), the recent folders/files feature actually works, Windows store apps run in windows like normal programs (no more confusing full screen dual OS crap) which means they look and function no different than desktop apps. There's a notification center, so you can get email/twitter/skype/whatever notifications without need to keep those sites/apps open 24/7.
Plus, there's DirectX 12 which will make future games run significantly faster (and due to the free upgrade will likely become widely supported much faster than DX10 and DX11). MS is also going to make it easy for win32 apps to be ported to the store, which means safer apps without bundleware (goodbye Ask toolbar) and 100% clean uninstalls. You'll also be able to sideload store apps (if the dev allows it), so you can get all the safety of the new app model without having to use the store.
