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.

Omega auto unit
Rolex 3135 auto






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

Rolex classic red reverser wheels







Omega reverser wheel second from right




worn auto reverser wheel








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.


Overall both auto units are well made and have good power reserve, but my choice is the Rolex.