I wrote about the iPhone 6+ earlier in the year; at the time, I wasn’t sure if I would like the device and would I actually return it because it was too big.
I’ve now been using the device basically since its launch, and have travelled a reasonable amount with it (South Africa, Dubai, US). In short, I think this is the best iOS phone experience you can have right now. I did try an iPhone 6 for a while, but it felt very much like an incremental upgrade to the 5S, as opposed to the 5S - 6+ upgrade.
If you’re considering it, go get one! You won’t be disappointed. If you’re looking for an Android device, right now I’m a huge fan of the Motorola line (I’ve used the 1st gen X and G). But I only hear good things about the Z3 line from Sony.