OK, maybe someone can clarify this. I have my Mac in a guest house located only about 100 feet from my cable modem/router combo. However there's lots of glass in the way so I have a Cisco/Linksys extender located in the guest house that can pick up the signal just fine. It's a dual band router but I just use the 2.4 GHz band because the 5 band won't get that far. Looking at the utilities section of Wireless Diagnostics, when I scan for wifi I see three bands; the two 2.4 bands and the one 5 band. Ordinarily I stay connected to the extender's 2.4 GHz band. Sometimes, though, that extender will crap out and the Mac will connect to the other 2.4 band. Here's the question. When I'm connected to the extender band, Utilities shows excellent quality with a transmit rate over 140. When I'm connected to the 2.4 band not coming from the extender, Utilities shows poor quality with tx rates in the 30 to 50 Mbps range. That makes sense. Here's what doesn't: when I use Speedtest I get download speeds of around 7 to10 Mb/s using the extender band with excellent quality and high transfer speeds; and download speeds of 26 to 32 Mb/s using the house band with the poor quality and low transfer speeds. Now I realize that using an extender affects the bandwidth in some way, but I guess I expected that it would affect both connections equally, while it appears to only affect the extender band. Can someone make sense of this? My inclination is to just not use the extender as long as I can connect, regardless of what the utilities show me.