If I was going to spend about $600 on a phone, I wouldn't put it down on a Sony device. Don't get me wrong, I love the company, but I don't think its prices for the past year or so have been realistic and I would fear the huge loss in resale value. But that's just me. If you like Sony, this deal should be right up your alley.
The unlocked Sony Xperia XZ with a US warranty is down to $580-$600 on Amazon. When it was first released, the XZ was priced at $699.99, but we saw its price drop to $649.99 in October. Now it's down another $50-$70, depending on color:
I think the blue one looks great, but then it's also the most expensive still. As for what you're getting for that much money, here's the rather underwhelming spec list: 5.2" 1080p display, Snapdragon 820, 3GB RAM and 32GB storage with MicroSD slot, 23MP and 13MP cameras, stereo speakers, Android 6.0.1 Marshmallow, and 2900mAh battery. Keep in mind that this currently counts as Sony's flagship. Shipping is free on Amazon, so you won't have to worry about that at least.