Sinn Durability

[Carl]

My Sinn 856 UTC simply stopped working one day so I mailed it off to the authorized Sinn repair shop for a quote on reviving it. The funny thing is that the quote I received was identical to the one the same shop sent to me three years ago, almost to the day, when the UTC previously croaked. I'm not questioning the repair shop since they have to evaluate all incoming cases by their internal processes; however, three years MTBF is not a good indicator for Sinn, or at least this model. Is this a matter to take up with Sinn, or should I just chalk it up to bad luck?
BTW, the UTC is my "B" watch that I occasionally wear as an alternate to my trusty root beer GMT Master, which I have worn for over three decades. I have the GMT serviced (PM) every 8-10 years and it has never failed me. I am not comparing the Sinn with Rolex, but there are plenty of watches out there far less expensive than the Sinn that can run more than three years without failure.
Thanks for letting me bloviate!

[Theothergreg]

Sorry to hear that. My U1 runs like a champ after over 10 years and never been serviced. It has been diving in various spots over the world, has experienced harsh east coast and midwest winters, and I even dropped it off a table at SBUX and put a dent in the tegimented U-boat steel case, with no adverse effects.

[Carl]

Thanks for your reply! So far, it appears I have a Zitrone!