Best camera - Sony Xperia Z2/Z3C or LG G3?

[tjmckay4]

Looking to buy an android phone from an iphone 5 (don't want the samsung bloatware). We have got twins in the family and want a phone with a better camera including 4K video, also bored of Apple iOS.

I've narrowed the choice down to either a Sony Xperia Z2 or Z3 compact or an LG G3.

Considerations:
- I've gotta convince my wife to sell her iphone 4 to take my iphone 5 so I can buy the phone so cost is key, so I can't afford the Xperia Z3.
- I already have a Nexus 7 2013 and love the stock android clean interface.
- The Sony Xperia line looks good – Great camera, 4K recording, waterproof, etc.
- The LG G3 camera reviews really well, rated more highly (from what I've read) over the Xperia's.
- I need/want a phone that has speedy focus and shooting with an easy to access camera app/button.
- I want to future proof myself so I'm keen on 4k video recording.

So...

- Is the LG G3 too big to handle, fit in pocket etc. over the Z3C or Z2 (can't afford Z3)?
- Is the waterproofing on the Zperia's a good enough feature?
- Would I be sacrificing a better interface and form factor on the Sony's just to get the better camera on the LG G3?

Hope this makes sense. Comments appreciated.