This was a 14 day trans-atlantic from Ft Lauderdale to Rome with 4 ports: two in the Azores and two in Spain. I've done over 50 cruises and about 10 were on HAL. I've always liked HAL's vibe - which is to appeal to seasoned travelers who appreciate discovering new places. I like days at sea and purposely picked this smaller, older ship after being on the Nieuw Statendam last summer (whose promenade deck is virtually useless with no room for deck chairs and extremely narrow in many spots, plus limited views of the water). The two things that I particularly enjoyed on the NS, and was looking forward to on the Oosterdam, was the food quality and the Music Walk, specifically Lincoln Center Stage and BB Kings.
Main dining room (dinners): I thought the menus offered a good variety and each night there were several dishes that appealed to me. Ingredients were good quality (note that I only had beef twice but it was fine), dishes well prepared and presented. Enjoyed a cheese plate for dessert several nights - it's not on the menu, but another diner ordered it which reminded me.
Lido (breakfast & lunch): it was difficult to find things that appealed since many items looked dried out - for example, sliced cheese that was curling up at the edges, sliced meats that were turning dark from sitting out, pasta that was dried out, pizza was stiff and cold. Yes, I could have asked for fresh items, but that takes time and their quality control should have prevented dried out items from being presented. Breakfast pastries were good - flaky and flavorful. Note that the famous sticky bun is significantly smaller now (which is OK) but some kind of sickly sweet sauce is being used instead of actually carmelized sugar. Tried once and that was enough.
Interior on deck 6 - forward. I nearly always book interiors (solo traveler) and this was fine. The only frustration was that the TV was installed at an odd angle, so I couldn't watch it straight ahead. Not a big deal. Asked for foam pillow the first day which was provided, along with the standard pillows so easy to read in bed. Mini-fridge was very useful. LOTS of closet space.
I had researched beforehand and decided to take the local bus to explore the UNESCO town of Angra do Heroismo. Bus left near the main square (where ship's shuttle left us) and you can pay the driver. Takes about 50 minutes and the bus ride is a great way to see a bit of the island - up hills, down hills, through towns, etc. Angra was easy to walk around (a bit hilly) with a nice marina and churches.
Really enjoyed this port! Docked right in town so walked to the fort and military museum, very interesting building and exhibits. Walked to two gardens: Jardin Borges was very surprising because in addition to trees, shrubs and flowers it had various rocky grottos - lush green foliage with steep stony steps; A few ponds hidden among the leaves. Verdant mossy walls. No entry fee.
The official botanical garden was fascinating - mostly trees from all over the world. Huge, towering trees some with a huge circumference. Lots of paths wending through forest sections. Bamboo groves too. Portuguese tile plaques throughout explaining local history. Oh yes, several roosters with glorious plumage strolling around and cock-a-doodle doing.
Did a tour of the Alcazaba fortress/palace with Malaga Adventures. Only 10 euros and the guide provided historical context which i wouldn't have know otherwise. Easy to walk around the town, visit some churches, eat in an outdoor cafe and people watch.
Cartagena was having their annual marathon so I really enjoyed watching the runners - ended up sitting in a cafe along with locals and cheering them on. Went to the Casa de la Fortuna (House of Fortune) - several rooms from home of a wealthy landowner that have been discovered and the Museum of the Roman Theater of Cartagena - I loved this! Exhibits and timeline inside the museum and then you go out into the theater and can wander up, down and all around.