Hi Steve,
Just from my own experience with C. nobilior I treat them like my C. walkeriana's. They don't like to sit in water. The roots rot pretty fast when left damp. They do the best when mounted. I don't leave any of my C. walkers, or C. nob's in pots ever. They get mounted with no moss or anything.
I've tried both ways in pot and mounted. When left in the pot the roots suffered badly and the growth rate was stunted BADLY.
When I switched them all over to mounts they added growths and roots quickly.
I had heard at one time they were hard to grow. I figured I'd try cause I love species catts. I found out quickly that it wasn't that they were hard, just picky about growing mediums.
If your growing area is high in humidity or does not have alott of airflow to dry them out quickly after watering I'd suggest mounting them. You will have to water more often, but the root system you will grow for your troubles will be impressive