I've had this device for two weeks and I absolutely love it. This replaces a personal Note 2 and my work S4. I can do without a replaceable battery but a removable SD is a must. Everything looks, well, big, but does not compromise in quality. The second screen notifications are a blessing, I dont get interrupted while composing an email, checking the calendar, working with the terminal emulator, relaxing watching the tube, etc
Everything works super fast, I can use it with one hand (I have big hands).
On the downside it is not "scene" friendly. Still with some work it can be rooted and Xpossed can be installed. Custom roms cannot be installed unless you posses the US T-Mobile version or the European H960A (except France). Given the unique qualities of this phone I wouldn't advice installing a custom rom anyways.
Battery life is great if you are on Android 5.1.1, with a fresh installation of Marshmallow the battery still drained quickly.