Thanks for the responses. BTW, one of the other advantage of the "mesh" system vs the old extenders is that they do *not* establish a separate network SSID. So for instance, I can have the printer connected to the satellite and print on the main floor while connected to the router. That does not work with the extenders.
I finally installed the Netgear Orbi AC 3000 router and satellite today. Installation was a breeze. Immediately the Wi-Fi downstairs jumped from around 3-5 Megabits/sec to around 22-25 (out of 35 or so coming in). A tad slower than on the main floor but a definite improvement and enough for most purposes. Finally should be able to conduct online conversations with my overseas colleagues without interruptions. Pricey but worth it.
On the other hand, I got burned ordering the extra satellite in the Pro line. Beware, they won't connect to the router. Should have been more careful but then B&H stock either the Home router/satellite 2 unit package, or the Pro satellite. Makes no sense. Now have to ship back the satellite and find a way to order a second home satellite.