Its not just the warranty..the firmware is not readily available..for me, i dont care, I use third party vms...but it matters to some....
The real difference will be the image quality and until we see more images of the dahua at night, with shots that dont provide anything for the IR to reflect off, it will be hard to tell..its also important to see actual video...stills only tell a small part of the picture...at 90 dollars though these are a great deal, particularly since they offer SD card recording and audio connections....they may turn out to be better at night than the hiks, who knows...