Well there are large coin laundries around Atlanta full of Mexican's using Mexican detergents with total abandon in all the front-loaders. No argument, though, because they are heavy sudsers. When using in an HE machine you just scale back the dosage.
The Mexican detergents are not meant to rinse out office dust, so yes, there are differences in formulations.Most of the Mexicans do very hard and dirty work whether they are living in the US or Mexico. With or without phosphates I find the Mexican detergents superior performers. Viva remains my personal favorite and is the strongest one I have found. Ariel has a wonderful fragrance and I like to use it with loads of colored clothes in the summer.