I already have my 12-35mm and I'm getting the 20/1.7 next week specifically for my universal studios trip at night. for those who have owned both - in terms of micro-contrast/color/sharpness, which is better at its max aperture? i'm referring to visible IQ difference, not statistical significance. As for MFD - is it correct to say the 12-35 can focus closer than 20/1.7? Lastly, is there any aperture/shutter speed simulator that i can use, so that I know how much shutter speed i'm gaining from 1.7 to 2.8 at given iso? i tried a bunch of them but all of them had max f2.8.. thanks!