As a Peloton user (both the bike and fitness classes), I took the free month to try out some Fitness+ classes and see if it was worth subbing to. I love Peloton for spinning, but was open to the idea of using Fitness+ for other types of exercise since the cost is relatively low.
Overall I found Fitness+ to be pretty solid. It's a great foundation for the service, and as mentioned the value is so good that for the vast majority of people who really want to commit to exercising at home, this will cover your bases. I think the Apple Watch integration is fine but pretty superfluous. Having your heart rate visible is a great functional benefit, but otherwise stuff like closing rings and calorie counts don't really add to the workout so much as they add to the Apple lifestyle. If you care about closing your rings then it's a nice touch, but it itself isn't really an added benefit over other services. All that stuff has always been on your watch, just now it's on your TV. I also really liked that each exercise would show other people doing easier/harder variations. This is a super smart move that makes it a more accessible experience for newcomers.
On the flip side, I think it still feels a bit early and lacking in features compared to Peloton. It's not necessarily fair to compare a brand new service to something that's had years to grow and mature, but also it's Apple and they could have launched with every feature under the sun if they really tried hard enough. I wish there was more variation in workout types and lengths (every core exercise seems to be 10 minutes?), especially offering longer workouts for things like spin. I also wish there was more variety in music. Apple offers really broad categories like upbeat anthems/recent hits/hip-hop/classic rock/etc, while Peloton offers more focused themes like 80s pop/70s rock/New Wave/2000s pop punk/etc, plus a large selection of specific artist classes. I also wish AF+ had more camera angles for exercises, especially from the side. It's not always easy to gauge if you're doing a move correctly when you're looking at a person from the front. Overall, AF+ could stand to use a bit more technical language. Their tone and communication errs a bit too much on the hippy-dippy lifestyle side of things, which is fine, but a better balance of language that makes people aware of their body and how to exercise correctly would benefit the workout.
Overall AF+ felt totally fine. If you have Apple One at the top tier and treat F+ as a freebie, sure why not. But if you're looking to specifically spend ~$12 a month to subscribe to a fitness service and the convenience and mild savings from Apple One don't matter, I think the Peloton digital subscription is better in almost every way. Even if you don't have the Peloton bike, for like $12 a month you get access to their entire class library, which means more instructors, more music, more exercise types and class lengths, and a more robust feature set. You just need to look down at your Watch to see your rings close, which whatever.