I have service experience with all of those, and each one was light years better than Montblanc. Not only that, I will state that Montblanc offered the single worst service experience I have ever encountered with any product or any brand, and that includes those like Chevrolet and Dodge.
I accept and agree with you that all brands have all problems. But Montblanc is completely deplorable and not to be considered with other brands in this regard. For crying out loud, they returned my "repaired" 1858 floating in a cardboard box. Inexcusable and quite angering.