I have 4 (four) current generation Airport Extreme AC routers. 1 of the routers is connected to my modem, while the other 3 are set up to extend my network. I use my iPhone wifi settings to add the new router each time I have added another one. It always recommends extending my network, which makes sense to me. I just added the 4th router over the weekend, with less than expected results. We have TWC's 300mb/s internet. We can never pull that speed, regardless of how we connect everything. The fastest I have pulled is 250mb/s. Typical consistent speed on an "excellent" connection is around 200mb/s. However, now that I have 3 extenders, I can't get any speed faster than 100mb/s. I haven't had time to turn off the new router and see if the speeds go back up, but wanted to check here as well to see if my fears are correct. We have a large house, so I'm attempting to make sure there are the best connections possible, no matter where we are. Also, just to confirm, the repeaters are all connecting to the "main" router, correct? Is that by default? I would hate to find out that one of the repeaters is connecting to another repeater, which then connects to the main router. Maybe there are other settings I need to check, any help is greatly appreciated. Thanks.