Frontenac used to use the real CADPAT fabric for their BDU's (I'm not sure about the newer sets). The fabric is quick-drying and won't tear, even though it's thin.
Parklands uses a knock-off CADPAT print on cotton fabric. That means it still won't rip, but it will soak up the water. It's also more prone to fading with use then Frontenac.
Both use the BDU pattern (more or less) however the CADPAT print used by Parklands has alot more brown in it then real CADPAT. The one thing they have going for them is their selection in gear (jacket, trousers, boonie, etc..).
I'm not sure how much paintballing you do, or how dirty you get, so it'll come down to your preferences.