The slim fans are also Mishimoto (12"). They feel like they move a fair amount of air.
Judging by the specs posted online for both the SPAL and Mishimoto, they should move roughly the same amount of air for 12" fans.

However, because their posted specs (thickness) for the shroud are wrong, I was not able to use it and just have the fans installed straight to the radiator.

I will see if I am able to return the Mishi fans and purchase the SPAL.
Could you tell me what size fans are best and if you use a shroud or just the fans? A part number would be great.
* I was going to purchase the Koyo rad and SPAL fans, however I was warned that with the Kamikaze header, I would not be able to get any combination of fans/shroud to fit with the Koyo & Kami header.

My only concern is that my temps never changed from what I experienced with the stock radiator to the new radiator. This is what led me to believe that the intercooler might be hindering airflow. However, I will trust you on this if you say it will not affect the airflow. I will add that in order to get the intercooler to fit, I had to cut the black "fins" out of bumper. My thought was that these might stabilize the air and help it to go into the radiator rather than everywhere else.

Someone suggested timing could be increasing my coolant temps. I can send a datalog and my calibration, but I don't think that is the cause. AFR's are perfect and I do not have an EGT sensor.