Both hotels are very close to each other, the Dominican being a little closer to the Central train station (but only a few minutes walk closer).
Marriott is indeed starting to look a bit dated but still ok, rooms facing the courtyard are much quieter. Good breakfast too.
Dominican is more 'boutique' looking and more of an 'experience' hotel while the Marriott could be just anywhere, still a solid chain hotel though.
Courtyard is located in a quiet area (still walking distance to Central station) but not that much around, brand-new and good breakfast though (and much quieter at night as there are mostly offices around).
If I had the choice, I would pick the Marriott (but that's because I value a decent breakfast, especially while on holiday).