The recent bump in this thread reminded me that I meant to post on it a while back.

I had to use the WM customer service. I bought a bag from a dealer, and had some concerns about it. I called the dealer and they told me to directly contact WM, and gave me their number. I contacted WM, and spoke to someone there. I got the idea that they are a pretty small operation as the person who answered said that he needed to walk from the factory floor back into the office. At any rate I told him my concern, and he told me to send them the bag.

Turns out I was wrong, and they made improvements to the bag anyway (free of charge I might add) to resolve my issue. So from that one experience I can say that their customer service is excellent.

For the record I own 3 WM bags and love 'em all.