As a matter of fact my current perpetual gmt is the best timekeeper I ever owned. That being said I had a similar experience with a watch from different brand: it was a terrible timekeeper and the customer service couldn't find anything wrong with it. As you, I ended up selling it.
Beyer was one of the first Swiss Ulysse Nardin AD after Rolf Schnyder acquired the company. I was privileged to have dinner with both gentlemen about 20 years ago. I last saw Mr Beyer three years ago when I took my younger daughter to Switzerland. He was already frail back then and we visited him at
Cartier AD in Hong Kong sold me one at 30% off in 2003 and to sweeten the deal offered a mechanical Basculante at equivalent of 1600 USD. Tnat was before boutiques became a commonplace. How the times changes. And I still have both.
The power reserve hand on my watch is white and not black as on the picture you posted, so I have no issues seeing it. I agree on GMT and even 24 hours indicators. They are very small and with my aging eyes I can barely see them. The watch is very cool though and is one of my favorite travel compani