Hi Patrick,

Technically speaking there is no difference and no good or bad in this question.
From a functional side it is most likely the easiest (and best) to install your desired language. Why? English is installed by default and Odoo will simply add the language you wish directly. If you would choose the language English you would have to go to settings and install the language you're own.
So both are as 'good', it is just that directly installing the desired language is faster and easier.

Regards,

Yenthe