I've recently got one...
...and the following things occur to me.
Firstly, I ordered this through work, in a rush, partly on the strength of this review. Then when I saw the size of it in the shop, I tried to change my order. But I was too late, so I figured I'd run with it. And sure enough it is big. But not unusably so. It's slim enough to feel fairly unintrusive in a pocket, but the smoothness and weight do mean you need to keep a firm grip on it. I can cycle with it in a front pocket, though a smaller man wearing tighter trousers might prefer not too.
The camera is pretty damn good, but like all phone cameras, the sensor gives you that weird 'painterly' quality at full magnification. Still, it's the best I've used, and the extra pixels give you much more room for fixing those edges. The stock camera app is mixed - Superior Auto mode is fairly smart, but Manual mode offers a limited array of options. I'm sure this could be fixed with a 3rd party app. Disagreeing with this review, both modes defaulted to 20Mpx shots straight out of the box. The manual button needs quite a firm click, too firm when you need to keep it steady, and you'll find you're often accidentally holding it half down which hides the on-screen controls.
Waterproof is good, especially as a cyclist, since I've found to my cost that most backpacks are not. But I'm not convinced that the screen can adequately differentiate between the capacitance of a finger and a drop of water. It'll survive in the bath, but trying to use it will test your patience.
The battery life, however, is dead good. Excellent power-saving modes gave me a long weekend away without recharge, despite having the camera on for half of the trip. For me, that's a real plus. Of course, it's not replaceable, so time will tell whether it remains serviceable for the lifetime of the phone.
There's been a lot of talk about the screen. The screen seems good to me. Yes, you can read a text without picking it up off your desk. The viewing angle is fine, even if it may not be as good on paper as some. Taking photos where you can't get your head behind it is the only time this has affected me, but hey, it's a digital camera - just take a few at a few different angles. Brightness is on the pull-down menu, so only 2 clicks away.
The processor is lightening fast, and unlike some commenters, I've not felt the phone get hot (no warmer than my S3, anyway). I'm used to running Cyanogenmod, so I may not be up to date with the latest stock Android features, but the keyboard seems good, and texting is easy (though a link to additional dictionary choices would be good, and I've not figured out a way to force double letters). I do miss the Samsung's hard 'home' button, and the screen lock/unlock can be hard to find (being so close to the volume rocker).
In summary: If you want a shiny phone with a big screen, a good camera and great battery life, pick this. If you want something unobtrusive, lightweight and portable, or you'll really miss turning the screen on with a big Home button, don't. I like it, but not without reservations. So, any questions, ask away and I'll try to answer.