You have to understand, when you hear the specs, the phone is very underwhelming. Especially compared to phones like the LG G3 (4k screen resolution) and Note 4, BUT, when you SEE it all in action, how well everything works together, how good the screen looks, the camera, just everything, it's a huge difference from reading specs on a piece of paper.
1. The G3 doesn't have 4K, has qHD (4x 720p)
2. The Note 4, has qHD too, but not very true qHD... In fact, it has less sub-pixels than the iPhone 6+. The Note 4 uses pentille (2 colors per pixel), the iPhone uses full RGB (3), you can calculate the pixels yourself.
3. The G3 may have more resolution, but that's about it, and you won't see it, because it's way beyond human eye resolution... the iPhone 6/6+ has double the contrast of the G3.