I purchased the dual setup through CSG recently. I did a data log of my daily commute before and after the install. I figured the data may interest some, since I was looking for more.
Car has JDL UEL header ceramic coated, flex fuel kit, and DT tune. Both logs were done on 93oct.
Before Cooler: Ambient Temp 91F, humid day (no RH value)
After Cooler: Ambient Temp 98F, also very humid.
Overall, I'm happy with the dual rad/oil cooler. I'll log temperatures during my upcoming track event as well.