Slim Fast:
http://www.livestrong.com/article/125563-slim-fast/
http://www.fathead-movie.com/images/slimfast.png
https://tamafitness.files.wordpress.com/2011/08/shakeology_v...
Sounds like you could probably survive entirely on Slim Fast. It's got Iron (which the original Soylent didn't have), Vitamin A, Vitamin C, Vitamin B, Vitamin D, and Iodine, and a bunch of other micronutrients. You probably wouldn't have a great time but I doubt you would on a Soylent-only diet either.
Solyent doesn't seem to differ much:
http://files.soylent.com/pdf/soylent-drink-nutrition-facts-e...