I got the Lumia 1020 for Christmas. Cost me £236.95 (
here, though they've increased the price). I went from a 920 to this, and haven't had any problems at all. It works perfectly fine. My contract for the 920 expires in April, and I'm thinking of getting a sim only one till Microsoft release a flagship Windows 10 device that can replace the 1020.
The speed and everything works fine. I guess if you want to get the 930 / 1520 and wait for all the Windows 10 updates, you'll be fine then too. But I wanted the camera of the 1020, and got it when I did.