[javadog]

The Rolex chronographs used various versions of Valjoux movements for some fifty-odd years. A modified Zenith El Primero movement was used next, until Rolex developed their own movement which is used in the current models. You can tell which movement type is in a Rolex chronograph by the position of the dials on the face, as they were fixed by their basic position in the movement. Many (most?) chronographs used a Valjoux movement - they were considered more or less the standard in that type of watch for years, although the Zenith El Primero movements were arguably better.

I'd say that the majority of high end watch companies that do not manufacture their own movements use one from ETA, and most of them modify them to suit their needs. Rarely is a basic ETA movement used, although their are many, many different base movements to choose from.

The movements used in top grade watches differ significantly from those in lesser watches, both in detail design and the amount of hand-finishing that goes into their production. If you are interested in this sort of thing, there are a couple of publishers producing annual watch catalogs, briefly highlighting the offerings from the top 100 or so manufacturers. These books typically give the specifications and, in many cases, photos of the movements used in the watches. They are available at larger book stores.

Apart from some of the detail differences, what sets the better watches apart from the herd has to do with the degree that the movements are adjusted. Quite significant gains can be made in the fine tuning of the movement. It's the difference between a watch that is accurate to 1 or 2 seconds a day, or less, and one that might struggle to get within 7 or 8.

JR