Here is Xcruiser XDSR585HD, XDSR515HDR and XDSR685HDR 4K box comparision
Xcruiser has recently launched XDSR515HDR and XDSR685HDR 4K boxes. You can find all the comparision between these 3 boxes here
In short the different between 585HD and 515HDR box is that.. 515HDR box has Inbuilt Wifi and Card Slot.. and little advance is 685HDR box which has 2GB Ram and 16GB Memory along with CAM and Card Slots.
There is no change in Software between these 3 products