Unless you really need the money I wouldn't do it. In addition to all of the other points made, I would worry that if they are streaming a movie or vice versa, it will make it impossible for the other household to do anything. Also, we found that even if a router can support a lot of devices, when our kids visit, and add extra laptops, mobile phones, and tablets, we experience severe network problems. I do not think these home networks can handle the traffic of many devices. So if you want a way out or feel awkward since they are your landlords, just tell them your router is already maxed out and cannot handle any additional devices.