Plenty of articles online but the words of the "The Grand Seiko Guy" sum it up ..."there are two VFA models utilising the 4580 calibre. These models can undoubtedly be considered the absolute pinnacle of the entire vintage Grand Seiko era, and either of them would qualify without peer as the ultimate “grail” piece in any vintage Grand Seiko collection – not just because of their rarity, but also because the represent the ultimate achievement of what Grand Seiko was all about – creating quite simply the best watch on the planet "