The 5180 is indeed another special Patek reference, where engraving is pushed to the heart of the watch itself, and offers a beautiful, skeletonized interpretation of the 240 movement. However, while understandably most collectors are madly in love with Patek's out-of-catalog Rare Handcrafts, or the 5x31 series, or even this 5088, for some reason the 5180 has never "clicked" with some Patek enthusiasts....Hence I'm even happier that you appreciate this beauty! ;-)