Agree with the other responses. The 830 probably beats the 1020 in every way other than the camera. I don't think the extra GB of RAM makes a difference, I think its mainly for the camera and not really used for other functions. The screen type (AMOLED vs LCD) is debatable I suppose. I have a 1020 and love it, but if I was buying right now i'd likely go with the 830 over the 1020.
i think the comments above regarding the RAM is absolutely correct. 2GB wont add up anything. that 2 GB might be required only for 41 MPix photos.
further, if u are not into serious photography, 830 is absolutely fine with CZ lens for 10 MP and PureView Tech. further to add, i read somewhere about some improvement in camera allowing faster photos in 830, which makes more sense.
personally, i am not in much photography. i take photos of my family and some places i visit. apart from that some documents and office work. this doesnot require more MP at all. in fact more MP means larger photos, not easy to share. that's why i liked 720. camera with 6.7 MP CZ lens, u get clear and nice pics in really small size.
except camera, 830 is always a preference.