On my previous bike I used one, and it definitely extended the time to pain considerably. Just don't overfill it, it needs to barely have any air - just enough to help distribute the pressure away from the tailbone and evenly across the butt. I haven't bothered using it much on my R3T, for me the seat works passably as is, but the concept and the utility of them is solid, ie it's not snakeoil. They definitely work.
I've been considering the Airhawk R, that's new since I bought mine - it has gaps underneath the scrotum and would reduce pressure in that area, which I think would be helpful for me.