In terms of the most balanced in speed, consistency in page rendering and good default settings, is there a clear winner?
Personally I've been using both Dark Reader and Midnight Lizard on different devices and I can't say I noticed much of a difference in terms of performance, what I did notice is that Dark Reader seems to have better defaults, but many complain that it slows down page loading a ton, I haven't heard the same about Midnight Lizard, but maybe that is by virtue that it has way way fewer installations and therefore fewer people talking about it.
Do you know if I've missed one and there is a totally different extension that does even better than both?
I use one called Dark Mode. Before that I used one called Dark Background and Light Text, but it kept flashing white on pages while they were loading so I quit using it (this was years ago and IDK if this has since been fixed).