Sometimes you can take one simple look at a watch and know that it's one you have to have. Luxury watch owners are well-known for their taste and for knowing what they want from a watch. But it's not always that easy, and sometimes deciding between different timepieces can be difficult, especially if they're somewhat similar in their design. With that in mind, comparing some of the most popular watches is often a must. The Lange & Sohne Saxonia and the Patek Philippe Calatrava are two perfect examples of slightly similar watches worth taking a look at.