The 193 is Fantastic, while the 307 is Awesome.
193 is Gorgeous and the 307 is Beautiful.
193 is really quite Large, the 307 isn't by any means Small.
I would dearly Love to own a 193, I very much Hope to acquire a 307 some day.
The 193 would look Wonderful with a light brown Ammo, the 307 amazing with a dark brown Ammo.
Now a guess.... I think that the 193 is considerably heavier than the pam55, while the 307 weighs in at quite a lot more than the pam177.
The 193 is better looking than a Submariner, the 307 is a lot more attractive than a Seamaster (IMO).
I'm sitting at a Torvill and Dean performance in Nottingham, welcoming the Olympic Torch, I'm quite sure that Christopher Dean is not wearing the 193, while it looks as though Jane Torvill is not wearing a 307.
The 193 is on the left, the 307 is on the right. (assuming my earlier assumption was correct).
The most obvious difference is of course the time, 193 showing an AM time, the 307 showing PM.
Hoping to have actually spotted an 11th difference, 193 is a Tritium dial I think, but the 307 is possibly a Luminova ?
Cheers and Torches