after i sold my 808 then i bought my friend white lumia 920.later my friend bought 1020 white  color the same color like the L920 he sold to me.made few comparison.firstly the screen,L920 brightness,saturation and contrast is better then 1020 for my liking.the clearback amoled on 1020 doesnt work for me.then the speed is pretty much the same on 920 and 1020 since both are dual core.but still 1520 will feel lil bit faster coz the snapdragon 800 in it.and we did camera test on the 1020,seriously i really like the picture on my 808 more than the 1020.I saw few of 1520 photos on the internet,it seems to be pretty good despite the lesser pixel on the cam compared to 1020.if me i would go for 1520..but it's ur choice.