I have used all 3 of their primers before I started using the Vallejo primers, and they all work well...the white is a little on the thin side, but works, then again I have yet to see a white primer that doesn't look a little thin.
As far as their Black Base you use under some of their metallics....it goes on slightly translucent, but works well for their paints that require the gloss black under them. Some of the car guys here swear by it, and they were normally using Humbrol or Testors Gloss black enamels to undercoat Alcald, and even they say that the Alclad Gloss Black base works better. I have seen the results side by side...and while there isn't much of a difference, there is a difference in using the Alclad Black base....it does give that extra "umph" to the color coat.