Hi pressure drop, (3.1 if'n I remember right), difficult to put door back on after cleaning which is needed regularly. I was pretty much given one to try when I installed new system, had a SG2200 before.
I have customers who asked for them and love them. So I gave it a try. I was at training last week and watched folks fight to get the door back on, including the instructor. BTW, it was not a Trane/AS class. Just the system being trained with happened to have one.