I will start with the hardware. It felt very solid and even the body is made of plastic, it is very durable. Screen is big and with a nice resolution (AMOLED screen 4.5 inch screen, 720p resolution) . The camera area comes out a bit from the back but it is not that bad and still feels not as thick as the Lumia 920. And for the size it is not extremely heavy. The phone is as fast as a Windows Phone can be: very fluid user interface, responsive although due to the way it handles (or rather say it does not handle) multitask, sometimes you need to wait for a while every time you launch an app (Maps, Facebook, etc.). That can be a bit annoying specially when you have such a powerful phone.
A nice feature is the clock always visible. Double tab on screen and the phone will show the lock screen with your configured useful information as in all Windows Phone 8 mobiles
During the week I had it I was testing the camera and apps. From the app point of view, there is not much to say. One nice addition is 6tag, a fully functional Instagram client.
Regarding the camera, it is great to have Pure View now in Windows Phone. I think there is no need to get much into detail regarding the Pure View as it is well known: 41 Megapixel camera, 1/1.5" sensor, Carl Zeiss optics, Optical image stabilisation, Xenon flash and manual and automatic autofocus. One thing that most of phones still lack is the optical zoom. In the Lumia 1020 and because of the number of megapixels, you can always crop the image to substitute the optical zoom.
Here are some samples of pictures I have taken during the week. I think some of them are in higher resolution (I did not manage to find out how to configure the quality of the pictures I was taking). But you can click on them and see in more detail.
If you are a Windows Phone fan, I think definitely this is the phone for you! I would not hesitate! So far I will keep using my iPhone 5. But who knows which will be my next phone :-)