I've no experience with the two brands described, but unless they're sold as loss leaders, they must have access to cheap shot and powder. If one could buy Peruvian lead shot by the ton and powders manufactured with indifferent quality control and threat of lawsuits nil, the results would be very competitive products.
As do other posters, I handload to get the best possible results at a reasonable price, even though I still shoot a few factory loaded offerings, mostly in modern repeating guns.
The problem I've found with the cheap promotional loads is consistency. When my pet papers got wet in a cloudburst in the dovefield one day, I switched to a box of Winchester "High Speed" 7/8 oz. marked No. 8 shot. After feathering several birds with them, I finished up with some borrowed shells. Curious, I took five or six of the Winchesters apart, found them all loaded with No. 6. Shooting No. 6 in a crowded field is a very bad idea. I've also recently weighed shot charges from another prominent manufacturer's 1 1/8oz. loads and found them to be actually 1 1/16 oz. If these kinds of mistakes happen, what else might be wrong with them, like 13,000 psi?
