ABSOLUTELY worth it! Chops has amazing service and perfectly prepared steaks and side dishes. It's like getting a $50/pp meal for $20. Same goes for Portofino. The food in the main dining room is good considering they are serving 1,500 people. But it is more like catering food than a fine restaurant. The food in Chops and Portofino is more individually prepared. Live it up and book them both. I reccomend doing it for Carribean night.
Chops has a typical steakhouse menu. Fillet Mignon, NY Strip, Sirloin, Prime rib, etc. They also have side dishes of potatoes (huge), spinach, broccoli, asparagus, salads, etc.
Portofino has a typical italian menu.
Book em early so you can get the time you want.
btw.. I assume your taking Navigator or Mariner. I don't think they retrofitted Chops into the other voyager class ships.