Mobilsiden has compared the iPhone 6 Plus with the new Samsung Galaxy S6 Edge (using final release firmware).
There are some great shots from both cameras, and whilst Mobilsiden concludes the S6 Edge is the clear winner, I personally think both cameras take good photos and its not conclusive enough in its testing.
More comparisons are needed with people, movement, and general day to day scenarios. However, it still gives you a good idea of what both phones are able to achieve.
Via – http://www.mobilsiden.dk/nyheder/kameraduel-apple-iphone-6-plus-vs-samsung-galaxy-s6-edge,lid.34134/