I think it looks good on your wrist, you can definitely pull it off. I used to love that look, but not for me anymore.
Its all about what you think and feel about the watch. Because at the end of the day, you will be wearing it.
I can understand how you can be undecided. You will be happy with either watch. But think of it this way, if you want wrist presence, go for the PO. If you desire comfort and versatility, go for the 300m.
Or do what I did, buy a completely different watch.
😁
I had every intention to buy a new Seamaster 300m and went home with a Speedy Pro.