Hi.
Does changing backends has impact in performance and accuracy of emulation?
Thank you
Yes; depending on the game there can be positive and negative effects in games. Both backends have their strengths and weaknesses.
IS there a general favorite that does well with majority of games, or is just too mixed?
As far as I know, OpenGL is the best if the game doesn't need EFB to RAM. Otherwise, use DX11...
Also depends on your video card; if you have an Nvidia card, then almost definitely go with OGL for most games (but still try both out, you never know).