Htc one (M8) or Xperia Z2?

Hey there guys, first post on here!

As it's my first post I could do with some advice, first off I'm currently an iPhone user, I've had my iPhone 5 for nearly 2 years now and it's been great, but I think it's time to up the screen size and jump into the world of android, at least until the iPhone 6 rears it's head!

So it's a simple question really? The Htc one (M8) or the Xperia Z2? - they will both cost pretty much the same in the UK here, £30 more for the Z2 but that's not a deal breaker...

Here are the things that matter most to me :

Music - I walk to work everyday, 40 mins there and 40 mins back, so a decent music player would be great, I've used Samsung's stock music player before and it's disgusting, so I don't really want anything like that.

Design - I like the look of both tbh, Z2 is a bit of a block but I quite like that, along with the waterproofing (good for our wonderful English weather) But I know the HTC is well loved for it's design, I've held one before and it seems really great. Speakers on the front off the phone aren't massively important, I don't want to be 'that guy' who listens to music aloud.

Camera - The only thing that really pushes me towards the Sony here, I've heard such mixed things about the Htc one camera, and I don't want a downgrade from my iPhone 5. Also Slow mo! I love slow mo, gotta have slow mo! Do they both record slow mo sound as well? The 5s does and it always looks and sounds great.

User experience - Although I don't use an android as my main I have plenty of experience of the skins companies use to destroy the wonderful stock experience. I know the Htc has a massive sense skin, and Sony's is a little more stock style, but from the videos I've watched the Htc seems to run faster even with it's own skin on top of 4.4. I've heard rumours that Sony's kitkat upgrade is buggy as hell as well.

So there it is, I'm really torn between the two, I know the Htc one is universally seen as the best android phone to get with all it's awards etc, but the Sony I like for the water proofing and camera....

It's a tough one!

Any ideas?