There are many comments here on Leica service, but here is one
thing to remember. Leica warranty does "not" transfer to a new
owner. It is only for the original owner. Check the website,
and I was looking at purchasing a previously owned Leica and called Leica service and they confirmed it.

Swarovski and Zeiss do transfer to the new owner. Also Nikon
will cover your optic for 25 years.

Keep that in mind when buying preowned.