you know it’s not for me, i’ve played about 25 years, in fact i was playing PC games somewhere in '90, not counting zx spectrum - i don’t need to play, i want anyone could play the game that i produce and i feel that lots of people wil have to wait until new upgrade or new PC, and i don’t need that.
i did try to use Dx10 and opengl and result was bad for UT4, i had the same with P166 running quake without opengl support.
simple game can’t be laggy with any shaders. in fact unity uses also dx11, but they got dx9 support to render dx11 and they use SM1-2-3 and they got “hard” scenes, but i can program it to use simple models that will run on olpc, that’s what i can’t do with ue4.
and about dx10 support - after building a package i have to create a shortcut to use -dx10, because it will try to use SM5 that i didn’t built, but FPS difference between SM5 and SM4 is absent, while there’s no hard objects or many polygons with reflections and once again same project runs flawless in HTML5 behaviour.