My Z1 experiences...
I've owned this phone for around a month, since the date of its release anyway - coming from a Galaxy S3 this was a leap of faith... i've never owned a Sony product in my life save for a largely unused PS3 hack toy..
The waterproof works exactly as advertised, i've used this phone in the bath and shower, dunked it in many bowls of water at work (a colleague with the Z was too scared to ever try this!) and scared the bejesus out of my poor mother doing the washing up by "accidentally" dropping my fancy new phone in the bowl - this feature alone is worth the price of admission.
Performance is stunning, this is the fastest Android device i've ever personally had the experience of.. sure the G2 and a couple of others may beat it on paper - but i'd be shocked if you noticed, this thing is a powerhouse.
Battery is similarly good...i've never had it crap out on my like my S3 could occasionally do with heavy use.. in fact i've very rarely seen this phone anywhere near 10%!
Ok, enough Sony felating...the screen.. now the reviewer seems to think the screen is something special. And it pains me to say this but if screens are your thing buy any other flagship over this. For my usage model the screen is terrible sometimes... and it is all down to viewing angles.. sharp viewing angles make this display unusuable - not a problem you say? Ever have your phone on your desk, hear the notification and just glace to see what it's about? I did! Not with my Z1 though, physically picking it up and looking at it is the only way to do this.
I do love this amazing phone - but Sony need to really work on their screen tech as to me this is only just better than the original Z and nothing like the screen on the S4, G2, HTC One or Nexus 5..