I have had great results with Phase III dish, much better signals than say a round dish, I have never checked it against the old fiberglass two LNB dish, any time I see then I am switching them out, (I do have one here I use for three other satellites).
The mast has to be exactly plumb, use the small level that comes with it to accomplish this, near is not good enough, the tilt or skew is usually spot on for these parts, but the elevation sometimes needs moved up or down, remember these dish default to the 101 satellite and if every thing is done right the other two satellites should be lined up perfectly, I have never had a problem with them, I off set the mast slightly to take into account the weight of the dish as they are a bit heavier than a regular dish and can pull the mast off the plumb............ I am sure you will get it tweaked perfect!