Question on AO

I recently tried GTAO on COD WW2 and really liked it, due to its name and sudden appearance i was intrigued so i read around on some forum posts about GTAO. Long story short: i didn't get much of it, except claims that
it is a cheaper and more "realistic" AO than HBAO.

I'm kind of a newbie to this and personally i think it looks much better than HBAO but the second i turned it on in COD WW2 i instantly thought: "gee, this reminds me of MXAO".

Does anyone know the differences and similarities of the two?

Marty McFly wrote: MXAO (as you maybe know) is based on Alchemy AO and therefore, along with HBAO+ and ASSAO which all work more or less the same, state of the art of 2012-2014.
[...]
Current state of the art method of computing SSAO is called Ground-Truth Ambient Occlusion, short GTAO. It's a fairly new method from Activision, which is considered an upgrade to HBAO and tries to estimate the occlusion as physically accurate as possible.
[...]

(original post)

Hope it clarified your doubts.
Besides, in that same post, Marty McFly announced an upgrade to his shader MXAO, based right on GTAO method.
If you're interested in that, you'll find it being included in the qUINT collection. Just change the preprocessor value "MXAO_HQ" from 0 to 1 to activate it, like this:

Please for the love of gods, DON'T edit the preprocessor on the FXes, ReShade has the Edit Global preprocessor settings button for a reason.

Doing like this it is saved on the preset and won't need the FX file to be redistributed.