Training function matters in rear drive ellipticals because the longer rear-drive layout is valuable only if it supports the workouts the user wants to repeat. A smooth stride is useful, but the machine still needs the right resistance, controls, stability, and room fit.
A rear drive elliptical can work well for steady cardio, endurance sessions, warmups, or lower-impact conditioning. It becomes a poor match when the frame is too long for the space, the stride does not fit the user, or the controls make workouts harder to manage.