Legumes, in general, have a lot of phytic acid, which reduces our ability to absorb the minerals they contain. Soy beans are quite high in phytic acid, I think higher than many other commonly consumed legumes.
Since we're dairy and soy intolerant, we don't consume either. We don't use an actual milk replacement, in the sense of a glass of it, or over cereal. Rice milk isn't very nutritious so I only occasionally use it in baked goods, we use a lot of coconut milk in various ways, and if I needed a nutritious milky beverage, I may look into hempmilk.
I don't drink coconut milk straight, but it makes an amazing hot cocoa (can you tell I was craving a re-make of my childhood favorite?