No, it is not the most important thing. It might be for someone in a nursing home who is having trouble getting enough calories. But as a regular meal replacement, no, calories are a poor metric. Better metric is per calorie. As in sugars per calorie and protein per calorie. Even the somewhat improved Ensure Plus is way out of balance - 30% less fats, 26% less protein and 40% more sugars (yay diabeetus!) - compared to soylent 1.6. And don’t forget fiber. Ensure: zero grams of dietary fibre. Soylent: 7 grams per 500 calories or 28% of your RDA.
Pricewise, Ensure is also more expensive - the cheapest Ensure Plus I could find was $25 for 5500 calories, Soylent 1.6 is $21.23 for 5500 calories.
I think that’s unlikely. Especially given that it has zero fibre. A 0% fibre diet will have you shitting bricks after just a couple of days. Ensure intended to help sick people in nursing homes, not normal everyday consumption. But if you can provide a citation for those tests, I’m all ears.
Soylent’s not perfect. But it is definitely better than Ensure if you are a normal, healthy person.