I have used both.
i was vegan for a while and so had soy milk then, the thing I struggle with is that you can't get in in half litre sizes (you can overseas grrr), and with juts me drinking it the litre would go off well before I got through it.

Milo has been on soy this week though, so I have been having it too.

All the supermarkets near me sell organic milk. DH likes it, but the main one we can get is parmalat, and he doesn't like the company so he won't buuy that one.