Quote Originally Posted by J57ltr View Post
Tube and fin is like a regular regulator, Bar and plate are typically thicker and have fins on the inside of the tube as well to aid in heat transfer, therefore they are more efficient at removing heat.

Jeff
It is actually a balancing act!!
to my understanding, all else held equal the bar & plate design has less pressure drop and on the other hand, tube & fin is a little better at heat transfer. In the end, their performance on good cores is not really noticeable, just taste and economics