Orly is the better of the two Parisian airports with a much more lively and dynamic atmosphere. It has a much better passenger flow than CDG T1 and finding one's way around is relatively simple. There is a good selection of restaurants/bars/cafés landside. Checkin areas are relatively clearly marked and it is a fast process to departures for domestic flights. Security and passport control for international flights can be arduous due to staffing levels. What's good about Orly is that each checkin desk leads to its corresponding gate number meaning a short walk. If you've got time to spend at Orly leave security until just before departure because there is nothing to do airside.