Who here has used a Powertrain Technology hydraulic throwout bearing?

UPDATE: I have bled bled bled the system and it has improved to the point that i can force reverse in, and force 3rd and 4th gear while motor running but not 1st / 2nd. It just needs to push the pressure plate fingers just a little bit more, should i try a longer stroke master cyl?
Appreciate any advice, its whats stopping me from driving this car after a resto!
Thanks.