I wanted to share my experiences and see what others have found. I'm going to Paris in December. I bought a Paris Museum Pass and it arrived via DHL today, and I used that to secure Louvre admission time and a Leonardo exhibit time as well. Here's what I learned -- interested in others' experience.
- As covered elsewhere, Paris Museum Pass ("PMP") holders must book a reservation time and you need the PMP serial number so you can't book until you get the PMP physically in hand.
Louvre internet ticket site (ticketlouvre.fr) is INSANELY crowded and slow. When I went to the site I actually got put into a "Queue-It" window (which updated constantly) and it took 15 minutes before I could even get to the page where you order tickets. Every entry took three or four minutes to process. The overall process took one hour. (at 10 pm Paris time). The booking site also kept giving me a "generic error" message. When that happened I just re-entered the info and usually it went through the second or third time. Be patient!
Leonardo is sold out already through mid-November (three weeks away)
The ticketing site has a special link specifically for PMP holders to book a time to the museum.
Then (and this is where I'm not 100% sure) I booked a SEPARATE reservation for Leonardo, indicating that I was a free admission (due to PMP).
So bottom line I hope I've done this correctly: Two reservations, one for PMP admission to the Louvre and one for a slot to see Leonardo exhibit. Didn't pay for either.