You want the plan to actually use your Garmin data — HRV, Body Battery, Training Status — not just send workouts to your watch. Garmin Coach doesn't do this; CoachUpFit does.
You do more than running. Garmin Coach has limited cycling plans and no triathlon plans. CoachUpFit covers all four sports.
You want automatic ACWR injury-risk monitoring and race-week tapering tied to your recent load, not just a date-based template.
You're a female athlete who wants cycle-aware adaptation as a built-in feature.
You want a plan that changes when you skip a session, when you're sick, when your HRV is depressed — not one that runs on a fixed calendar.
You want "why today" explanations on every session, not just structured workout descriptions.