I tried using the WIFI link on my Canon 77D and full res shots were taking about 8 seconds to download to my PC using the Canon Software. Using Tether Tools tether cable and the same Canon software, the same shots arrive in about 2 seconds. I use the tether cable most of the time, but there are times when having a connected tether cable is cumbersome, so I sometimes go the WIFI connection. I have a larger monitor attached as my second monitor when working in my studio, and I have set it up to display the received image, as well as send it to the Canon Software that I use for minor editing. This Canon Software works somewhat like Lightroom, but it is available Free via download from Canon. To download this software, you will need to enter your camera serial number, so have it ready. Positioning this larger monitor so the model being shot can see it, seems to make a big difference in the quality of the shots. When she can see each shot, each one taken in a series seems to be better than the previous one.
Charley