I've read all the comments carefully and sincerely thanks to everyone for your feedbacks and suggestions.
Overall, the general sentiment seems to consider the money saving more than the OB experience, which is quite understandable. It's a pity because in Milan Boutique, all the people were really kind and prepared, without the veneer of fake kindness which sometime one could expect in such environment (I have personally experienced it in a Roelx boutique). However, to be honest I must say that maybe I will find the same also in the AD (at the end of day, it really depends also on people).
Regarding the second point (caliber 3861 vs future Spirate system), it seems that according to your opinion Omega will not change the Moonwatch movement over the next years, and if we look at the history of the Moonwatch, it is reasonable (maybe they will focus first on everyday watches, such as Seamaster Aqua Terra). Moreover, I have read that between 2025 and 2026, it is planned another trip to the Moon (where people will physically land on Moon's surface). If this will be done with current Moonwatch, my expectation is that the value will increase more, won't it?
Last but not least: how can I understand if the version that the AD will sell me is with the latest clasps or with the old one? I am not an expert of the difference. I thought that the last reference visible on Omega website was already the one with latest clasps, but maybe I'm wrong.