If you're willing to guinea pig, please try this if you haven't already. It's short on macro-nutrients, but perhaps it would pair nicely with macro-nutrient focussed substitutes. I'm interested in comparisons between how these products compare to the actual constituent ingredients consumed normally, but don't value the information enough to try it myself.
seems like way too little fat
Rob Rhinehart's food replacement Soylent now has a crowdfunding campaign.
If you're interested in one or more of these benefits, send in some money! There is also a new blog post.