Have the Leica 10X42s, nice glass fortunately haven't had any issues. Some friends have had Leica warranty battles, when I upgraded to 15X I went with Swarovski. They've been back for service twice (I'm kinda rough on my stuff) in 10 yrs. A big part of the extra expense is standing behind the product. Swaro may be the leader in CS. I've split the eyecups twice and torn the objective covers, 1 phone call had replacements in 3 days. Swaro offered to send loaners while they were being worked on.
Buy once, cry once.
