Over the next few weeks I will be doing a series of Blog posts on a head to head matchup between a Rolex Datejust 3135 movement and an Omega CoAxial Seamaster Pro model. I want to compare various design aspects of each watch and give you my opinion of which I like best and why. I will explore the Automatic unit, the escapement, date functions, crown and case tube, crystal and bezel, train wheels, balance and regulation, ease of repair, water resistance, overall appearance etc. Both watches have their pluses and minuses, I will point out the differences that I see since these are the watches that I see most often.
Automatic unit.
The rolex automatic unit has been a standard of excellence for many years. It is heavy duty, runs well, is quiet and works quite well even when a bit dirty. The Omega auto is also very well designed and does a nice job. It is a bit thinner and the oscillating weight is supported by ball bearings.


The Rolex auto is quite a bit more durable than the Omega, it has a replaceable oscillating weight axel, the Omega is supported by ball bearings, but is quite a bit more difficult and expensive to replace. Advantage Rolex.
Auto reverser wheels



The auto reverser wheels from the Rolex are much more durable than the Omega. The Omega wheel has proven to be a bit of a problem, if it goes bad, then the auto will either only wind in one direction, or actually slightly unwind itself when hand wound from the crown. Advantage Rolex.
Overall the Rolex auto unit in my opinion is quite a bit more reliable than the Omega. The unit is quite a bit more durable, parts are heavy duty and it works well even when dirty. The Omega is smooth and works well, but the issues of the thin reverser wheel are an more common problem.
Conclusion
Overall both auto units are well made and have good power reserve, but my choice is the Rolex.
10 Comments
Wes Pace
My personal experience is yes the Rolex is more durable but the Omega generally keeps better time. The Rolex has a far better band than the Omega. Just my thoughts!
Robert Lawson
Looking forwards to reading your comparison note series.
Robert Lawson Pensacola FL
Nick Diieso
Hi Mark,
Thanks for this – no concerns about the oscillating axle and the susceptibility of the Rolex movement to perpendicular blows? I’ve seen a few broken axels or cracked pivot jewels on the 3035 and 3135…failures on the Omega ball-bearing supported weights do not seem to run the risk of hitting the movement like their Rolex counterparts…
Tom Overfield
I am always interested in these comparisons. Rolex, to me, has seemed to make rugged but utilitarian movements in their lower end. Omega makes movements that are high quality for the price point. Maybe these are a bit of a stereotype. I’m interested in a comparison of the finish between the two mass produced movements in particular. Thanks for the post and upcoming posts!
Bob McCorkle
Mark, Thanks for the comments on the Rolex vs. Omega. I have no experience with Omega, but do with Longines. While in Vietnam in 1970, I attempted to buy a Rolex from the PX in Saigon. After trying for several months with no success, I was convinced that the Longines was a comparable substitute. What a mistake! The watch never performed as I thought it should and was not what I wanted. After 1-2 years I replaced it with a nice Seiko. A nice watch, but no Rolex by any comparison. In 1977, I was assigned to Germany and made a trip to Zurich and, after much thought and conversation with a jeweler on Banhof Strasse, bought a stainless Datejust. Finally, after eight years of wanting a Rolex I now owned one. I still wear my watch daily and it has never failed me and is still very fashionable. It was $325 well spent and a decision I have never regretted. I await your comparison with Omega, but my choice will always be Rolex.
Donny Kemick
Agree with Robert! Looking forward to the ins and outs of this comparison.
Ken
I am also looking forward to reading your observations.
Dick Casale
Have worn my Rolex Oyster Perpetual regularly for 31 years and with one cleaning it’s been a great dependable watch.
Nick Diieso
Interesting…I have found over time that the oscillating axle in the Rolex movement contributes to a vastly enhanced winding efficiency, but also can lead to rotor-bridge impact and debris on perpendicular blows and cracked axle jewels (I’ve had both occur). Indeed, the new 4130 Daytona movement eschews the oscillating axle for a bearing solution. The new OMEGA 8500/9300 series movements also use ceramic bearings and upgraded reversers. I would assume that this takes the edge long term and addresses your concerns? Interested to hear your thoughts.
Dafoos
I recently broke a 9300 axle. Very disappointed as it was certainly being used more gently than I use my Rolexes.