I honestly never found Xert hard to understand. You punch in your progression rate, when your target date is, and follow the workouts. Is your needle pointing straight up? You’re on track. To the right? You’re ahead and can take some time off. To the left? You’re behind and should consider a longer/harder workout to make up the deficit. Throw in a hard effort to feed it breakthroughs every month or so and it’ll know how you’re progressing.
I found it all to be dead on in terms of my numbers and I felt incredible after only a few months of following it/mixing in my own outdoor work. I only cancelled as I had previously subbed to TR for a year and couldn’t justify paying for both, once my TR year is up I’ll go back to Xert full time. It’s so damn flexible, I don’t need to schedule a workout like TR does, I just jump on and it’ll tell me what I should be doing. They even have phone apps now so if you’re on the trainer it’s super easy to do a workout as it functions exactly like TR does with their phone app.
Could it be presented better? Of course. Their UI isn’t up to the level of TR, but that doesn’t seem to be their focus at all. It’s functional for what it does and their focus is on analysing the data as best they can for optimal results.