[chris russell]

Originally Posted by The GMT Master

Omega, for example, might have a more high-tech movement (in the form of the cal. 8500) than Rolex's equivalent (cal. 3135), but in my experience, it has been having some quite notable teething issues. The previous generation movement (cal. 2500) went through 3 iterations (A, B and C specs) before they resolved all the reliability issues. Rolex, on the other hand, has been using the cal. 3135 for about 20 years now, albeit with a few tweaks here and there, most recently to the hairspring and shock absorbers. However, it is very accurate, one of the most rugged and reliable movements money can buy, and very easy to service. Parts availability in the future will also be excellent, so as such, it is very hard to beat a Rolex movement. Yes, it might not be as pretty as some other movements, but as a workhorse, you can't get much better.

Omega did have some reliability and other related issues with the 2500 movements, partly because they incorporated the 2-layer variant of the Coaxial escapement in order to fit it into the base ETA 2892. The more ideal 3-layer CoAx escapement is used in the 8500 movement, which in itself was designed more along the lines of the Rolex approach with larger bearing surfaces and thicker gear-wheels for better long-term reliability. So far as I know, the 8500 has been performing admirably. In my experience it's the only mechanical movement that is as long-term consistent and accurate as the Rolex movements, both the 4130 and the 3130 Series.