Dlink makes me angry, if is as you described, they should write it in the description what HDD are supported and up to which capacity. Also term "shareport" DSR has it in FW , but they dont support it and they dont need the APP it self as other cheaper routers - no word about it. Also nothing mention how to access the HDD after is connected, had to write to dlink support to tell me to use IP address.
BTW: even in CZ support they had no idea up to which HDD capacity they support - is not documented for customers as well for local support
I really regret that i went with dlink again, thought the TOP in the serie and most expensive would have all their crap sorted out. But is still the same story...should go with Draytek - much better UI and Support- just to compare , check that all they support via USB - samba,ftp and even filebrowser and the top is you can install some torrent client to the router!
About the NAS storage - i would give another 200e to get some, also not all of them support 4tb drives, then not sure how is it with NTFS support. If it uses EXT i need to store somewhere 4tb of data - no place for that. To operate it i need still some PC to access and set and stuff. So ive ordered Android PC Minix 7 (around 80e) , i can do all and much more 3xUSB so i can connect any drive and go the NAS job.