UDS Terra Cotta Diffuser user question

I am thinking about trying the 16" terra cotta diffuser method on my UDS.
How high up above the charcoal should it be?
I have 2 grates in my UDS.
Would it be better to have it a couple of inches under the 2nd grate?

I read in another post that said the WSM has a pan 8" down from the bottom grate. That person seemed to like that dimension. Another placed his right on top of the charcoal basket. Others had some terra cotta plate cracking issues in that position. These were older posts. This is why I was asking for actual current user testimonials. I don't want to waste the money spent by just setting it in there and it falls apart from the heat or causes it not to cook properly.