I think you will find that your fellow passengers on a European cruise will be a really varied mix of nationalities which can be great fun. I would expect it to be a bit more formal dress wise, and as others have mentioned, as it will be port intensive the vibe around the ship will be different to the Caribbean. Not better or worse just different.
Depending on when you are going the Euro 2024 football tournament is being held in Germany, if your dates coincide expect any bar with a television to be packed and if it interests you at all the mix of Europeans on board will create a fantastic atmosphere.