The Studiofix Powder foundation is great IMHO. It gives medium coverage. I found that I get better coverage if I use the NARS Bronzer Brush or any kabuki brush. The MAC #129 does not work as well with Studiofix IMO.
Studio Fix and Studio Tech both give a medium to full coverage. I usually use SF for those who tend to have normal to oily skin and ST to those who have mnormal to dry skin and also for mature skin. IMO, both are great its just a matter of texture and the person's skin type.