I'm staying with SL for now.
Among other reasons is the tendency for some apps that run on newer OSs to display tools and text white on black. At my age I cannot read that stuff, that's why I have just purchased Adobe Elements 11. It retains black on white.
In other forums users have made complaints about white on black to developers of "Affinity" "Pixelmator" et al.
I'm beginning to wonder "Is Windows really so bad, especially if you can run stuff that needs no Internet connection?
Is it since Apple put a bean counter at its head that their emphasis is heavily biased towards sales volume and short-term margins (pop music and, IMHO, trivia) while neglecting the (admittedly smaller) base of those who want to achieve something after a day in front of a screen?