Do you use it as the occasional convenient meal replacement or how far do you go into replacing all real food?
I suspect there is both, but what I am getting at is how much Soylent's long-term success depends on people seeing eating as a nuisance that should be optimized away versus something that should be savoured and enjoyed.
To me this is in the context of the larger question of personal utility maximisation. In the grand scheme of things, we have just started being able to really monitor and improve all aspects of our lives (in terms of time spent, convenience), and there is the question of how far we (most people/potential customers) ultimately want to go. It has become clear that there is the potential to optimise away friction/time spent in almost all human habits, but it is not yet clear if we really want to keep going down that route.
Will we keep optimizing things like meals just because we can until there are (conceivably) nutrient implants that make eating unnecessary, or will we sort of revert and see that maximising utility of every interaction does not lead to overall greater satisfaction?
In one world, Soylent could eventually dominate, in the other, it will remain a niche product because eating and food is too important too most, also culturally speaking.