I was faced with the same issue before my first rm purchase... And after some consideration and discussion, I finally got myself rm10 over the other models. Here's the thing, the size of rm05 is relatively too small for a guy who wears 44mm panerai for his daily beater. My best friend bought an rm05, and he gave the watch tomhis mom after he purchased rm11 earlier this year, and he told me that the watch looks even better on his mom's wrist!
As for the rm16, I love it but it lacks of rm.'s DNA... The toneu (not sure if i spelled correctly) shape... It might be a great addition for your collection as your second rm, but I highly suggest you to go with rm10 for the first one....
Just my 2 cents...
Best regards,
Alex