I never go with what the latest fads are, have used Meguiars products for years now. But this place makes its own, is local to where I live currently and thought what the heck. They also have way better clay bar than what you can buy at " those other parts stores" I got the medium cut which is for older vehicles etc .
But anyways try them out hopefully take some before and after of the engine bay after I detail it
in regards to the clay bar, I know for a fact they do not make their own. there is only one manufacturer of detailing clay in north America and everyone else rebrands their clay.
the clay you got from them may be much more aggressive than the stuff on parts store shelves, so be careful with it, (aggressive clay will sometimes mar the paint and require you to polish the paint), that is why most clay in stores is very fine grade.
if you don't plan on polishing, test the clay somewhere out of sight (such as the roof), then you will know if it will mar the paint on the rest of the vehicle.
our jeeps have pretty hard clear so I doubt marring will be an issue on it, but paint on fords, gm's, and a lot of the Japanese and Korean cars is soft and will mar easily.
if you find that it is too aggressive for your paint, use it to clay the windshield and windows, (makes a huge difference when applying glass sealant or rain repellent).