I had a chance to play around with the Galaxy Note Edge and here are some of my thoughts.
All of the reviews I've seen so far on the Galaxy Note Edge seem to agree that the extra convenience afforded by that curved edge is more or less nullified since it makes the phone more awkward and difficult to hold - especially for lefties and ambidextrous users.
Which brings me once again to my biggest gripe with Android: those touch-activated Menu and Back keys straddling the Home button. For me at least, these virtual buttons make Android phones (especially the bigger ones) more difficult to operate with one hand. Not only that but a lot of times when I hand my phone to somebody to show them something, the first thing they do is accidentally tap one of these keys, either popping up a menu or kicking us out of the app we were using.
The all-physical buttons on the Galaxy S5 Active gave me hope that of all the Android OEMs, Samsung was the one to finally come to its senses, but now it seems they've taken this flawed touch-key philosophy and applied it to the entire right-hand side of a phone as well. And if that's not bad enough, they have the audacity to charge a premium for the inconvenience.
I was almost ecstatic to see Samsung adopt the flat edge design for the Note 4 (and I still think Apple was insane for abandoning it on the iPhone 6 and 6+). A device on which nearly all of its face is touch-activated needs to have a solid way to grip and hold it without inadvertently activating something, and to me, the Galaxy Note Edge is a step back in that regard. I just wish smartphone manufacturers would stop obsessing about ways to reduce thickness and focus more on making phones more comfortable, ergonomic and durable.