I am lucky to have two Pateks, a 5165 Aquanaut and a 6000G Calatrava. The Calatrava has been stored away for my wedding or my 40th, whatever comes first (the way things are going that will be the 40th then!). So I only really 'know' the Aquanaut at this point.
I absolutely adore the watch. I had some doubts at first, should I dig deeper and get the more iconic Nautilus, was the rubber strap a bit naff for such an expensive watch etc.? Anyway, each time I wear it I love it more. It is my favourite watch in my collection and I would happily keep it over the Calatrava or any of my other watches.
Quality is sublime and I have only ever seen two other Aquanauts being worn. One, my watch broker, who sold me my one, he has the bigger 5167 on bracelet, and another bizarrely been worn by a French tourist at Ku De Ta in Bali. He noticed mine and came over to talk watches.