Have been drinking it as my breakfast/lunch replacement for the past 5 months. I absolutely love the flavor. There are times when I crave solid food, but when I get through a bottle, I'm pretty satisfied and happy that I kept to 400 kcal for those meals.
They just released a coffee version, called Coffiest, that has L-theanine in it that is supposed to be a caffeine that doesn't cause jitters. I'm not sure on how well the caffeine interacts with me as I've never been one to get jitters or be actually feel the effects of caffeine. However, the flavor is so delicious. It tastes like a black coffee/mocha/original Soylent blend.
They actually just came out with a bar as well. It is 250 kcal. It is aptly named 'Soylent Bar'. It is supposed to have a caramel/salted caramel flavor from what I've read. I haven't bought it yet, but there are times when I'm hungry in the mid-morning/mid-afternoon, and I don't want something from a vending machine.
When it comes to nutrition, it really comes down to how much you are eating of it, how many supplements you are taking, is this your only source, etc... I haven't been on a strict diet of Soylent, so I can't vouch for how a 100% diet of it is. However, I've been relatively active, and my body hasn't reacted poorly to it or gained any weight from it.
Anyway, I just love the ability to grab a bottle for breakfast without thinking about it, and eventually when I get the bars, I will love having that as my go-to snack. If you PM me, I can send you a referral that gets you 50% off your first order of Soylent 2.0. The referral system only gives you a perk and not me. However, they donate 4 meals for hungry children for every new subscriber.