I like em, ALOT!!! My 501 carto's that is
I am a happy camper and will not squash the mailman today.
I like that I don't have to peel the paper off the cartos to fit in my tube thing with the riva type model. They fit snug over the top but once I pass the top of the carto it slides right on and I still have good airflow. I say thins because I know many people, myself included use 808 cartos with adapters and have to peel the paper off the carto to get enough airflow with the tube thing.
I like messing with stuff , it is like my hobby now. But when I get to the point where I have to goo gone paper off cartos , that gets old.
I will definitely be ordering these again from EM and a Riva too.