Building our new home in the north east and installing the heating myself. I ran into a lot of opinions on the need for heat transfer plates and the difference they would make. I ended up using the Zurn extruded aluminum plates and wanted to share what I saw when borrowed a thermal camera from work.
The engineer who designed the system for me had me use plates in about 75% of the house but in order to save costs (they were around $6 each) there were spots he said I could do without. The images show the areas that have plates against areas that don't.