The stock plates do have some slop. What Danny is saying is that it's useless slop. You'd have to slot the strut tower to allow the stock plates to move where you'd need them. When you have the stockers jammed into the corner of their holes, that essentially makes them non-adjustable (in terms of allowing you to dial-out neg camber and get adjust meaningful caster).
It's kinda like my seat track - sure it's adjustable. But I have it jammed through the rear-most adjustment and my knees still hit the dash. Adjustable, but not functionally adjustable for me.
Well, if you take it to an alignment shop (and you SHOULD), don't let them start grinding away at your strut towers to align it. And YES, alignment shops do this. Just tell them that you're getting a/m plates later on & that you don't want the tower's ground up.
Yep, the CC plates definately allow for proper alignment - they use the old holes as a foundation for new bracketry to align things properly (like how seat-track extenders use the old holes but shift things rearward).
Justin's right about the grinding of the OEM holes. It's supposed to work ok, but who wants crap like that done to their car. And when I've heard that referenced, it was to get some caster with a stock ride height. With a dropped car, neg camber can creep in bad, which isnt a big issue with stock ride height (in other words, it'd take more grinding on a lowered car).
The stock plates do have some slop. What Danny is saying is that it's useless slop. You'd have to slot the strut tower to allow the stock plates to move where you'd need them. When you have the stockers jammed into the corner of their holes, that essentially makes them non-adjustable (in terms of allowing you to dial-out neg camber and get adjust meaningful caster).
It's kinda like my seat track - sure it's adjustable. But I have it jammed through the rear-most adjustment and my knees still hit the dash. Adjustable, but not functionally adjustable for me.