I'm looking at the M8, the Nexus 5, the Sony Xperia z3, and the iPhone 6
Which one of these is the best phone? And please don't suggest phones that I didn't list, there's a reason I didn't list them.
Things that are important to me:
Battery
Good form factor/design
Camera
Performance
Sound quality
Thanks!
Posted via Android Central App with my Samsung Galaxy S5
Form Factor/Design: The form factor of the iPhone 6 hits a sweet spot for me personally. Not too tall, not too wide. The design I need to see in person first. I'm still a little unsure of the antenna strips. But design/form factor is completely subjective. You're the only one that can decide what looks and feels good in your hand. I've got the M8 and it's definitely no slouch in the design department. It's a beautiful well-made device. The other 2 you mentioned don't do anything for me design wise. The Z3 is overall too big, and the Nexus 5 just isn't very interesting looking.
Battery: Battery life on the iPhone 6 is rated similar to the 5S, but a little better. It's hard to say what real world battery life is though. The reviewers don't really get enough time to tell what long-term battery life is. The M8 has good battery life. I honestly haven't heard anything either way on the Z3. The Nexus 5 would probably be about in bout the same as the iPhone.
Camera: The camera is tricky. I'm gonna say the iPhone 6 and the Z3 will be the all around better cameras of the 4. However, the M8 takes great portraits and low-light shots. That's more important to me personally than landscape or more artistic photography. The M8 needs tinkering with to get good shots outdoors in bright light. Sometimes all you need to do is tap to focus on different parts of the screen to adjust white balance, exposure and the shot and it'll be fine. Other times manual mode may be necessary. The iPhone and Z3 won't have as much of a problem with that, but the Z3 lowlight shots aren't on par with the M8. Not sure about the iPhone in lowlight yet. The Nexus 5 shots I've seen aren't very good to be honest.
Performance: The M8 is blazing fast with no UI stutters or hiccups unlike some other skinned Android devices. The Nexus 5 is smooth as well, but I think the M8 is a little snappier. From what I've seen in the 6 it's really quick to. iOS has always been really smooth IMO. The Z3 I'm not sure about.
Sound Quality: You're not gonna beat the BoomSound speakers on the M8. Sound through the headphones is also great. In call quality sounds a little metallic on my M8 though. I rarely use my phone as a phone though, so that's fine with me. The iPhone 5S has great in call quality. Very natural, sounds more like a landline more than a cell phone. Call quality on the Z3 and Nexus 5 I don't know about. The sound quality of the iPhone should be loud enough, but it's single speaker isn't going to produce a full sound.
Personally, I like iOS and Android, so if I were choosing it would definitely be either the iPhone 6 or the HTC One M8. I don't really think you'll go wrong with either. If software updates are a big concern for you the Z3 might not be the best option. Sony has the poorest of the 4 when it comes to update reputation. The thing is, I'm pretty sure a new Nexus is just around the corner. If you really want stock Android and can wait, it may be a good idea.