I tried this out on my system, but it was Driver Version 310.90.
It hindered performance after following all steps.
The shinier effect looked pretty, and on Imperial Fleet it was nearly lagless, but nearly everywhere else my FPS dropped 20 to 30.
Of course it did. SGSSAA is one of the AA methods that has the most impact on performance. It's basically Supersampling AA and therefore calculates the frames at 2x your resolution, then interpolates it to fit your screen.
I recommend SMAA