How much does acing help your application?

Say for instance a school's median MSAT is a 192 and their error average is -2. Would getting a 191 or 190 but with 0 incorrects far just as well as a 192 within their error average?

[190/191, -0] = [192, -2] ??

Acing is a huge benefit to your application. Aces sometimes get in with lower scores like the example you just described. Typically though, it only provides a 1-3 cushion; if you're 5 points below a given MSAT median, I don't think acing it makes much of a difference.

I think acing makes a huge difference, especially towards the high end up the scoring bracket. A 212 with -2, will be seen the same as a 210 with -0.

i've personally heard of people getting into Newton with 208 aces.