The problem with Edge is that it's so far behind IE and other browsers, and the pace of development is too slow.
It's great to break from the past, but the UI is so bad (Favorites not presented as a tree, no right click on back & forward to get latest 10 sites, astoundingly bad settings),
It's amazingly buggy (tabs that won't close, videos that miss more and more frames as time to goes by, so watching streaming or videos longer than 10minutes is highly frustrating).
On Windows Phone, its terribad. The tab handling is dumbfounding, and very often, pages opened from other apps (Twitter) do not load correctly in Edge, and refresh is sometimes your friend.
We'll probably have the Edge a Windows 10 customer was expecting at the launch of the OS in 2017 or 2018.
For now, just look at the browser Microsoft employees use at Build and elsewhere, and it's not Edge..
I want to love this browser because we need competition in the browser market and because it's the Windows phone browser, and I'm using it everyday concurrently with Chrome.
But please fix bugs and bring it to a decent level feature-wise before working on the fancy things that at most are nice to have, not must-have.