How to choose
Short stays (≈1–3 days) often use Easy top-ups or day tickets; a weekday-heavy week may suit a week pass. Whether CDG/Orly legs are included follows the current official rules — as do loss/refund policies.
With one-axis days
A pass is not permission to cross axes. Prefer walking inside a district; Metro only for axis changes. Day-trips (Versailles/Disney) need their own ticket math.