I was resigned to running cat6e up three floors because there was only coax and I needed a wifi AP up there. Came across the moca solution and it's great. I get flawless 2.5gbe from the basement switch to the third floor over coax. It's basically a little device that connects at each end of the coax and cat6 goes in and out.

Cat 6 would be better though so I could run POE from the basement switch to power the wifi AP, and instead I need to go do a much more complicated switch (cat6) -> moca adapter + power brick to power moca adapter -> coax -> moca adapter + power brick (cat6) -> POE injector (with power brick) -> wifi AP. SO I'm adding at least three power bricks to the setup, which is annoying. Otherwise it would be one cat6 drawing POE from the switch and powering the AP.

+1 on MOCA 2 being excellent to solve gaps in wiring. We bought a 6000 sqft 2001 house built with in-wall RJ11, lots of coax runs and some Cat5e runs (but not enough). Due to the size the house, the electrical, HVAC and cabling is roughly divided into two halves with separate electrical panels, HVAC pads, etc.

Unfortunately, all the RJ11 and alarm wiring runs to a closet in one half while all the coax and Cat5e run to a closet in the other half - with no RJ11 endpoints near the Cat5e/Coax closet and not Cat5e/Coax endpoints near the RJ11 closet (sigh). I tried Powerline data and it only works well in adjacent rooms and not at all between the halves due to separate electrical panels. Fortunately, there were a lot of coax runs set up for two separate nets (18-inch satellite and a huge attic antenna for OTA broadcast). So, by repurposing the now-unneeded antenna coax, MOCA 2.5 gbps mostly saved the day by filling in where the Cat5e should have gone but didn't.