I used meet.jit.si once but my own server mostly and I couldn't tell you the difference in user experience. Seemed exactly the same.
Video: The default install sets up for 720p. It seems to start notably worse and then scale up to 720p within a minute, often much less. Some congestion control thing I expect.
You can set 1080p or other (lower too) resolution limits if you like. I tried 1080p but at ~6-7Mbit per connection outgoing my home internet 18MBit upload got saturated pretty quick! The default 720p has worked ok for up to 6 people for a few hours at a time. 1 of the people was Europe-to-Australia and seemed like anyone else. No huge lag times but some lag as you'd expect from that distance.
Audio: I note this separately as it seems to be handled separately by Jitsi. We've noticed it seems to tick along pretty well the same the whole time, whether the video is going up or down in resolution due to congestion or not. Audio quality seems fine. The mic makes more difference in quality than the audio codec.
Apps: Have a requirement to go into setting and put the URL for your own server. Otherwise it defaults to the public one. Bit awkward. It seems to suck down a lot of battery but I haven't benchmarked it against anything else. Maybe this is normal for camera/compression/decompression/display/network all at the same time?!
Other niceties: can share desktop/application, has a text chat side option too, has "hand up" indicator if someone wants to indicate they wish to speak - not that we've ever used it.
All in all, it works well for home personal use with 6 people so far. Definitely handy to have and I intend to keep one running for the future. Being able to send a link to my friends and show them my desktop, or vice versa, is handy if nothing else.
Edit - added App section