I’m a big fan of TrainerRoad. I’ve used it for a few years now. The new adaptive training and train now features are perfect for me. I use their calendar and enjoy the podcast too. They also have a fantastic forum that seems to use the same tech as this one. They seem to listen to their customers, constantly evolve, and do a good job of making it feel like you “know them”. I also really like that they lock customers in at the price from when they signed up, so as prices rise, loyal customers don’t pay more. If you like group settings, they also allow you to setup group rides where everyone is on cam and doing the same ride together (at your own ftp). I feel like there is just a ton of value in a TR sub.
I’ve used Sufferfest, but it’s not for me. People who like it REALLY like it though. I don’t really like their videos and I like to be able to pick my own entertainment (music or Netflix). One big advantage that SUF has is they offer strength and yoga content, not just cycling. I don’t really have a lot of negative to say, I just personally prefer TR.
I’m not really a Zwift training fan. Their plans just aren’t very good (random intervals, sessions tied to specific dates and times, etc.) Their world building is beautiful if you want to just ride, and if you can get past knowing that everyone is cheating, they have a ton of racing options for you to push yourself.
I really like the Xert workouts, and I love their data fields for the Garmin. They use different terminology than all of the others though, and that creates a frustrating barrier to entry. You really have to invest time into studying their model and method, listening to podcasts and googling for info, or pay a coach to do that for you.