That thing does breathe. See the exhaust fan on the right corner of the box? That little fan moves a lot of air.
Since I haven't had to get inside the box, I'm not sure yet how much work it will be. But it is quieter.
The reconfiguration of the heat exchangers changes the layout a bit. Also, the diverter valve has been redesigned to improve reliability.
If you look at the floor you will notice that the floor is now covered with a glued down rubberized mat. I'm very impressed with this. It helps with sound deadening and provides a durable, slip resistant surface.
Thanks, Randy, for posting the pictures.