It depends on the type of water you catch them Don.
I certainly would not eat catfish caught from some of the gold mines slimes dams. They have cyanide in the water.
I have eaten African Sharp Toothed Catfish from clean waters on a few occasions. The flesh is not unlike salmon and is nice and pink with big flakes. It is full of Omega 3 and is very good for you.
The most delicious of all the catfish species is a fish called "The Butter Barbel" which is found in the Limpopo River and parts of the Okavango in Botswana. I have eaten a fillet once in my life and can assure you it is truly fantastic.
Unfortunately this species is very endangered, due to modern farming practices.