Nexus 6p vs Xperia z5

I'm having a real hard time deciding what phone to get next. I'm coming from an HTC M8, which has been great, but it's old and the screen has gone.

I'm looking for a sim free phone. Big points for me are good performance, battery life and a good camera. I don't game too much or at all really, but I tend to take a lot of photos. Hence why I've ended up with these 2.

I think I'm leaning towards the Z5 because of its camera, expandable storage and it's waterproof too which is a bonus, but I've heard such great things about the Nexus and it gets great reviews, and Sony phones don't usually come with a great rep.

Also if theres any others I should consider let me know (I've looked at the OnePlus 3, its delivery time is too long for me, need it within the next week or so).

I'm based in the UK so Xiaomi phones are a no go for me unfortunately.

Thanks!