...at the time they were still around and you could grab them: why not?
There is an IWC Ingenieur 866 with - what some sources tell - a pilot's watch prototype dial that - as the story goes - IWC used to pitch with the German Airforce. It is said that they made 6 of those. I grabbed two of them. Just like them, they look wonderful. Is the story behind true? I do not know. Will it be easy to pick another one up some day? Probably some far-away-day.....
Oh, this is by the way what I am talking about. And it has no military markings, just to be totally transparent.
I think it all comes down to collecting what you can personally relate to: design, brand, history, rarity, etc.
Cheers, HSTE