Down Home Furry Con had live video streams and chat on Twitch and Picarto, with Discord for general chat. Couch Con and Mini Con 2020 were run on Discord with panel rooms within Discord. (Note that there is apparently a different Couch Con happening in June that comes up in web searches. I don't have a website link for the Couch Con that was this weekend.) I should note here that I didn't spend the whole weekend online watching these cons so I probably missed a lot. I simply checked in on them to see what was going on whenever I had time.
Of the three, Down Home Furry Con was the most professionally run. They had a full schedule of panels. Although there were some delays and some panels ran over time a bit, every panel I checked actually did happen and was well-attended. Couch Con and Mini Con, on the other hand, more hit or miss. They had some great panels but they also had no-shows. I noticed that a few panelists gave up and left because there was no one in the panel voice chat at the start of the time slot. I do sympathize because it is tough to talk about or demonstrate something to no one but in the future, I hope they at least start doing something and see if an audience trickles in.
The most fun panels, to me at least, were the games with audience participation. While I could stand to watch a game demo or an art stream for a while, it isn't as interesting to me if I'm just watching and not doing something. I noticed a problem with a few of those panels too. Some artists have a tendency to stop talking when they start working on something, which doesn't come across so well if it is a tutorial. I think it would be good if they explained what they were doing while they were doing it because it is not always obvious what's happening in the screencast. Other good things to mention include why one technique is better than another technique and what to do if you make a mistake. Generally, try to anticipate questions that the audience may have but may not have thought about asking yet.
Another problem I noticed was in the game voice chats, some people were casually tossing around racial and homophobic slurs. That only happened early in the weekend and after that things toned down a bit, so my guess is the problem had been dealt with behind the scenes.
My take on virtual cons is those don't compare in any way to actually traveling to a con, seeing your friends, and experiencing con events in person. However, I still had an interesting time with them this weekend and I'm glad that the virtual con organizers took the time and effort to make those happen.