You can access the detailed information on each of your Milo's from the Mobile App Dashboard.
The Wifi Speed of the Milo is very dependent on the Signal Strength. There is a tradeoff between the distance between Milo units and speed, where signal strength certainly plays a critical role. We typically look for a signal above 70% as a best practice. There is no correct answer here and each system is different. As signal strength increases the speed may also go up, but it also makes no sense to have your Milo's too close together.