Transmission Cooler

Alright, I've been reading through all the threads with decent info that I can come across. So far I haven't come to any real conclusions. What are the noteable differences between the finned and stacked. Do you prefer one over the other? I'm currently looking at B&M and Hayden units. Not sure what type I should go with here. The purpose of this little venture is to keep the tranny as happy as possible with 33s and stock gearing. The correct gearing will happen, but not with enough quickness that I want to forgo the cooler. I've got a Autometer Cobalt Gauge sitting here waiting for me to make up my mind. Thoughts?

I believe that the stacked plate style is a more efficient design.
Here's an interesting forum thread I saw discussing it all.
http://www.eng-tips.com/viewthread.cfm?qid=72270&page=8