I’ve only been using it for a fortnight, but the workouts are a good mix of difficulties and can be adjusted when needed. I can add/remove/swap whenever. I love zwift, and the integration is great. The forum is lively, and support tickets are quick and easy.
Is it as good as a 121 coach? No but it’s a tenth of the price. Would ChatGPT be as good? possibly if you teach it, and are prepared to create workouts on Zwift, manually diarise and amend.
For me TR really is the sweet spot, and seeing the calendar/career refresh is a real motivator.