that guys should stop putting DT in their reviews if they didn't actually go all the way.
However, it is a difficult skill to learn and clients should not expect it (unless I guess if you are paying for PSE) and never force it like in those movies.

Here is the provider that you want:
http://stephaniaricci.com/

It is a learned skill...and somewhat is just possible or not.  Takes some planning too...many variables.

I don't doubt the difficulty or acquired skill associated with it.  

Lets just stop calling ever BJ where someone takes it in past the head ad DT BJ...cause it ain't.  

I dated a girl for a bit that had no gag reflex...and there is a huge difference.