I have had very positive experiences working with the Leica store in Bellevue, but have also had to be patient with servicing. Definitely go through them as opposed to sending them in yourself. Usually, for cleaning and/or repair, they've gotten them back to me within ~2 months.
Just a clarification, Leica does not currently offer or recognize a lifetime warranty on their sport optics. I believe you get 10 years, limited warranty, from date of purchase.
I inherited my dad's 10X42 Trinovids and then managed to get water inside one of the "waterproof" oculars after an accidental submersion. I sent them in under the 10 year limit, but Leica deemed them "unrepairable" and said that they would not replace them. They offered I think a 50% discount on a new pair, which I opted to go with. That was a bit disappointing...
I would say that my experience with servicing/repair of Leica products has not been fantastic, but has also not been abysmal.
May the* F*lu*OR*escen*CE* be with you! - Nathaniel Peters Ph.D. University of Washington <ncpeters...>