We are travelling in July and know that The Louvre will be PACKED. From the forums I understand that the security lines are often the big line-ups and one way to save time is getting guided tour tickets that have a different check-in point when available.
I'm reading reviews on "skip the line" tickets offered by outside companies and it sounds like the tickets have to be picked up elsewhere, you need to return audio headphones back to the other location after, etc....it sounds like all that alone would be a hassle and a good chunk of time.
As you still need to allocate your desired time to enter The Louvre to the "skip the line", I'm wondering if these tickets are still using the same lines that a timed ticket from the official website would use? Is there some type of advantage to actually paying the increased price to the outside company rather than going direct and buying a timed ticket from The Louvre website?