I watched a documentary on Soylent. Personally, I'd rather not live on a thing that's composed in an old factory building where rats are running around and that has not gone through extensive testing. This is my health after all, the most important thing.
So technically I'm eating Joylent as Soylent only ships inside the USA :(. I did research before I bought a batch of Joylent. The conditions seem better but I wouldn't worry about Soylent. I saw the documentary with the rat too, that was probably because they'd only just rented the place; there wasn't proper infrastructure there as I think they'd just begun setting up what you can't even call a factory yet. I'd love to see up to date photos and videos of how they make it today; I'd expect it to be far cleaner and more controlled.