Huel is a meal replacement available in powder or liquid form: human fuel to supplement or replace whole foods. We all recognize that "real food" is best, but we can't eat organic grass-fed fair trade locally sourced whatever all the time. We'll leave aside that whole issue and focus on what Huel claims to be: "nutritionally complete, convenient, affordable food with minimal impact on animals and the environment."
Nutrionally Huel calories are 37% carbohydrate, 30% fat, 30% protein and 3% fiber, from a vegan mix of pea protein, gluten-free oats, medium-chain triglycerides, brown rice and other stuff. Huel is nutritionally complete from a macronutrient perspective - think all the amino acids - so it can compete with whey, the gold standard of protein supplements. That doesn't mean it contains all the micronutrients that you get from real food, so it's best to use it as what it's designed for: supplementation.
Huel is definitely convenient. The powder mixes easily with water using their shaker cup, or even better a dedicated shake blender like our good ole standby Hamilton Beach. Huel is also available in a ready-to-drink liquid bottle for 400 quick calories on the go. Both powder and liquid have a good taste and consistency, even when at room temperature. You get the oat and vanilla flavors strongly, and if you want to alter the taste Huel will sell you flavor boosters that do about what you'd think they do. They do use Sucralose for sweetener, and we know some people find that offputting although it didn't bother us. We had no problems with gas or the like, although all powder drinks affect some small percentage of people in that way. Note that Huel powder is low FODMAP, but the liquid isn't.
So nutrition and taste, check and check. When it comes to impact, that's a lot harder to judge. There are studies that show organic agriculture is better in many respects, but Huel is up front that their products are not organic. They do provide copious information on ingredient sourcing, so we'll let you be your own judge on this issue.
Overall we found Huel to be at least as tasty and convenient as our other preferred meal replacements, and the cost of Huel is competitive with other high-quality alternatives. We also appreciated that Huel is very transparent about how their product is made and what it is designed for, a refreshing change from a lot of nutritional marketing. If you're training hard and need the extra calories or just need the occasional convenience of a meal replacement you should give it a try, particularly if you're looking for a vegan/vegetarian option.