Having recieved my order I had a fun time testing those different bottles:

Diplomatico Reserva Exclusiva (Euro 33,49 incl. 19% VAT)
Very dark, a very balanced mild taste, hard to believe it has 40% alcohol in it as the taste of it is almost non-existant

Flor de Cana Centenario 12 Years (Euro 21,70 incl. 19%VAT)
Quite dark, not so fruitful and tasty as expected but still good, definitly taste the alcohol
and

Pyrat XO (euro 35,49 incl. 19%VAT)
The aroma is very orangy, the alcohol is quite present. Not as balanced as expected. Still very tasty.

Overall I would say that the 1st one is the Diplomatico by means of a balanced taste. But also it is 3rd in regards to recognizing it as a rum, for this to be the case it is too mild. (That bottle was emptied very fast with great joy!)
2nd is the Pyrat XO as its taste is too much in a single (oranges) direction. With the alcohol being quite present there was more respect to it and it will last longer...
3rd is The Flor de Cana, a quite decent rum with a nice taste to it. Also works well for aromatic cocktails.

Now I am curious how to get the really good stuff which those islands keep for themselves.