To vacuum the CAT, I have a vehicle detail adapter that is for getting into small spaces in cars, like the a/c vents grilles. I attach that to the end of my ash vac and then lie on my back and vacuum the CAT from the front. I do this one time per week or two. The issue is that it has to be done installed. If I want to remove it and vacuum from both side, I have to remove it and that adds considerably more time and the stove has to be ice cold.
Before I bought the steel one, I spoke with Condar and they were emphatic that the steel one requires less cleaning and will flow better. They do not make one for my stove, but they referred me to the one that I purchased on Amazon. The rep was pleasant and helpful. Hopefully, she will be correct regarding the flow and maintenance. The center of the CAT definitely gets some flame exposure at times, so I am hoping that this will help. I think this CAT died extra early because I had it replaced under warranty and the CAT had moved forward in the tray and was getting pounded by the flames until I realized it. Once, I started pulling them in and out, I realized that the CAT should be pushed in deeper and less in contact with the flames. But, even in the proper position, where it is now, it can still get flame contact.
So, hopefully, steel will hold up better to that.