The Patek 5054 looks beautiful, but I read on a previous forum several complaints about this watch, which I will excerpt here. Were/are you concerned about this possible problem ?
"The known (for the Cal. 240 used at 5015/5054/5055/5085) "Sudden Death" effect started. Even though the power reserve would be at 40+ Hours, the watch would stop. Then, I would slightly move it and it would start working again. My watch was brand new from the factory and still gave this problem after only a few weeks. In conclusion, I loved mine (5055) and I think its one of the most beautiful contemporary Patek, but the frustration associated with the sudden death effect was so high that I had to let go of it."
"I had a 5054 that did that. It would just stop with plenty of power reserve then start again. Seemed to be random. Had PP service it but the problem came back."