In my (not altogether uncommon or unfounded) opinion Patek isn't what it used to be and their product has suffered as a result. The Lange is the better watch (despite the problems I've heard with the brand which exist in many places but that fact does not excuse bad service anywhere) because it is better finished, detailed, and carefully designed. For example, the calendar apertures bug me with the way the text looks like it's getting spaghettified into a black hole. The one annoying thing about the Lange is that it's a horizontal clutch which means starting the chronograph will on occasion mean the second hand stutters. But other than that, I think it's the better buy.