I wasn't a fan of Yosemite, and I don't see El Capitan as an improvement compared to Mavericks or before, but it does seem better than Yosemite to me. Almost tolerable in fact.
Observations:
- The fonts, to me are clearer
- The idiotic, overly aggressive translucency seems toned down
- The contrast with the "glaring white everywhere" that seemed present in Yosemite is toned down.
- The controls now at least have slight 3D effects (but unfortunately, so do text input fields…Jonathan Ive just doesn't "get" standards, as far as I can tell!)
I don't see this as an improvement compared to Mavericks and its predecessors, but I might be able to tolerate it. With Snow Leopard through Mavericks, it was visually like I was eating a fine meal. Yosemite was like eating a meal made of canned Tuna. This, at least looks like it's a hamburger. Not quite what I wanted, but at least tolerable.
One caveat: Display preferences are now "dummified." You can't really configure anything with your display. Apparently Apple is targeting the IQ less than 70 crowd. If you're a photographer or you need to be able to configure your monitor for exact color profiles, say bye-bye to Mac OS X! I guess the focus of Apple is to make everything as stupid as possible.