Welcome to the forum Nails.

I'll preface my comment with the fact that I'm a huge Carrera fan. I'll then go on to confound any expectations that may cause and side with Steve in recommending the non-date Speedmaster. The vast majority of current Carreras don't have enough in common with vintage Carreras for my liking - but then I'm a vintage fan, you may decide that broken DNA doesn't matter to you in the least!

The Speedmaster was around before it became the "Moon" watch and Omega may lean heavily on that heritage, but then it is real and genuine, and at least visually, the links with the watches worn by Apollo astronauts actually on the moon are clear. Not that you're likely to wear it on a Velcro strap around a bulky airtight jacket! So again, you may decide none if that matters to you either.

To close then, I'll agree with Stewart, it's all about the watch they appeals most to you at the end of the day. Try them all on, see how they feel, how they look on your wrist, and then and only then, buy your favourite and enjoy it! You might consider vintage too - with a mechanical watch, you're looking at ongoing servicing costs whether modern or vintage.