need to understand options for RN104

I have inherited two RN104 devices and am struggling with the very limited user interface (The browser interface). I'm at the point of needing to buy more devices, but I'm not willing to sink more $ into this if I can't figure out a solution to the UI issues.

For example, I have a backup configured on one RN104 that copies one very large file (350 GB) to another RN104 over the WAN. There is no 'progress' indication I can find - and it's taking 40+ hours so I need to know 'are we close', etc (at 7am I have to stop consuming all the bandwidth). I assume there is a more detailed set of information somewhere, perhaps in a command line interface? I was hoping to find client software that would allow me to have a better user interaction, but I can't seem to find one.

I have the most basic needs - windows file server backup target, and NAS to NAS replication; no video, music, streaming, cloud, MAC/PC/phone clients ... should be easy!