@davideotto The price difference between the RLN36 and RLN16-410 is simply that the RLN16-410 is preloaded with a 4TB HDD which would add £80 (100USD / 95Euro) to the cost; also the RLN16-410 has 8 POE ethernet ports whereas if you use the RLN36 with POE cameras (which you should as they are better than DC powered WiFi cameras) then you'll also need to pair it up with 1 or 2 POE switches. So the comparison is really RLN36 + 4TB HDD + 8port POE Switch is £145+£80+£55=£280 compared to the RLN16-410 currently £272.

IMO the RLN36 is a far better option as you can add as much HDD as you need and if you need >8 POE then you can purchase 1 or more POE switches to suit