I did it last year and hated it. Felt really cheated by the end.
The testing phase is fun and interesting but the rest I thought didn't live up to their claims at all. Part of what I hated has probably changed now - it was very new in the UK, so the app and "coaching" was full of awful "you go girl!" american-ness and was written as though targetted at 2-year olds. They had a lot of feedback about that so that's probably changed.
However, the "coaching" isn't coaching - it's just a low quality chatbot telling you very obvious things. I hope they've done something better with AI functionality now, because it spends a lot of time asking you questions like "what did you have for breakfast" and when I did Zoe you could type in "800 donuts" and it would just say "that's a great choice!".
As other people have said, the "personalisation" is very dubious. The basic advice you get will be pretty much identical to what is said in the Zoe podcasts - it's basically telling you to eat a Mediterranean style diet whatever your results. I had poor sugar control and excellent fat control, but even with that they give meat low scores which I'm sure is ideological, not based on science.
The overarching message is very much "eat real unprocessed food" but the app is set up to make that really hard to log. Buy processed food with a barcode and it's snap and save (although when I did it, UK brands were very hit and miss), try to enter natural foods and you are endlessly searching for things that won't come up unless you phrase it exactly as they have entered it. Put something like "pork" in and it'll give you no results unless you can type an exact cut of meat etc. Scoring results could be very hit and miss - one brand of pickled onions would be red, another green. etc.
There is almost no guidance on where to start with eating a personalised Zoe diet. They give you about 10 good and bad foods - based on what you ate in the testing phase, so inevitably you get told not to eat white bagels, which you had to eat a lot of as they were the test of "bad carbs" so you really knew that already. They do nothing to help you discover new good foods. It's just guessing things, putting it into the app and seeing what it says. It has no meal plans or proper recipes - it just links to randomly generated ones on Allrecipes or similar that are American foods, in American measures and have about 30 ingredients that would cost you a week's budget and generate tons of food waste if you had to go buy it all for one plate of food.
The way the app works also means that it encourages you to just add more and more random things onto your plate to bring the score up. I found the mechanics of that pushed me towards bigger portions of foods I wasn't enjoying (everything ended up with random nuts and seeds on top, whether it suited the food or not), rather than helping me find the basic staples I could make normal meals out of. Even though I was reaching the targets Zoe gave me, I ended up gaining weight while eating food I didn't enjoy at all!
What I got out of it was simply that lower carb diets are a better choice for me. Other than that the advice is no better or different from anyone else who recommends real food, fruit and veg, fibre etc - which is basically every diet ever.