They are very different watches for sure. The PO is thicker but has more of an elegant, refined feel in my opinion. The bezel action is a perfect example, the PO feels much like a rolex, silky smooth and crisp but the SM 300 is harder to grip and requires more effort. I also prefer the PO’s handset to the the 300M but that’s just personal preference.
For what it’s worth I just bought my first PO a few days ago and now I’m going to sell the Seamaster I bought last October. I just know it’s not going to get enough wrist time now to justify owning it.
In terms of moment, i haven’t had the PO long enough to really compare but i will say the accuracy on the Seamaster is fantastic, easily one of my most accurate watches. Was my most accurate Omega by far until i added the 50th anniversary Apollo 11 speedy (steel/gold version). They’re basically tied but I have no reason to expect the PO to be any different.
Ultimately you should go with whichever model you like the best. If movement is a concern I’m sure they’re a wash in terms of reliability. The other difference is you can adjust the hour hand of the PO without hacking the movement. Nice touch if you travel.
