I agree with all of the above comments. It's still remarkable to me that automatic watches like Rolex and Omega can keep reasonably accurate time without the aid of a quartz crystal. While it's true that a $30 Timex or Casio would be more accurate, neither watch would have the character and class of an automatic.
Since both Rolex and Omega have excellent workmanship standards (with Omega slightly better IMO), I would say that the decision should be based on who you want to impress. If you want to impress the uninformed, common consumer, go for the Rolex. If you want people to acknowledge that you've done your research on fine watches and that you are not another lemming jumping off a cliff by paying $4K for a watch, get an Omega for $1400. For me, the Omega was the best overall choice in quality, price, reputation and aesthetics.
When I recently compared my SMP to a Rolex Oyster Perpetual, I noted the following differences:
1.) The SMP has a sturdier bracelet -- the links are solid instead of hollow
2.) The SMP clasp has a more secure latching mechanism
3.) The SMP has a cystal that is practically flush with the bezel -- this makes it less prone to chipping
4.) The Rolex has better looking hour markers on the dial -- but they don't glow like the SMP