Carbons'll probably help you more at the 60+ Distances, Platinums are good up to 60, depending on poundage, it might not be worth shelling out on carbons just yet. I'm shooting platinums at the mo, and they go more or less where I put em (the grass was where I wanted to put those misses, m'kay?)
Once I hit 80 Yards, I'll be getting some navigators, those are well nice!