That ain't pretty, for sure. But BBB is not exactly the place where people go to leave good reviews. It's the place people head after a negative experience.
This would be a much more straightforward conversation if the OEM radiator were still the same quality as the radiator the truck came out of the factory with. My shop told me the same thing that I've read others post here - the radiator they currently sell as OEM is not a high quality part at all. You've got the option of the Mexico spec version, supposedly better, which is still a metal/plastic design and current retail price is $100+ more than the aluminum Mishimoto.
The guys at Toy House where I service my truck had good things to say about Mishimoto, especially the all aluminum. There's a few unhappy customers for every product out there. Hopefully I don't end up one of them, there's also plenty of happy ones.