I’ve been a Xert user for about two years and I’m satisfied with the system, despite the difficulty of having to create a parallel dictionary between the language used in the books by Coggan and Allen and Joe Friel. I believe Xert could make a transition of concepts to maintain the same features, which are great, but in a more accessible way (reducing the learning curve).
At the very least, they could give the progression chart (XPMC) a more user-friendly look. If we compare the interface that XERT offers with, for example, Intervals, we see that XERT’s interface is not very user-friendly: the chart is confusing and heavy, and it doesn’t provide a simple field to check form in relation to the zones (fresh, risk, optimum). Right now I´ve been using XERT + Intervals because Intervals graphs are more friendly.
Also, there could be a specific help topic to explain the equivalences between Xert’s metrics and the usual terms (Friel, Coggan, CTS). At the same time, quick-tip buttons about these terms could be available in the app. The way to success is not to isolate, but to integrate.