We've got a very similar device, a Heos water, bought in Germany - and it's great. When I fill the tank at home, in particular - I just connect it up, let it fill while doing something else, keeping an ear open for it nearing full. And with a stop valve fitted to the hosepipe, just take it off the connector and walk back to turn off the tap, without getting wet.
Less benefit when filling on a site, but even then it makes it a 1 person job with less risk of getting wet!
