Have never been there. What is there? Where are the best beaches, shopping, etc? Is it easy to get around. Can you bargain with the cabbies? Is it possible to rent acar at the dock. If so, from who do you rent>? Is there any way to contact a car rental in advance?
All I can tell you is that those two islands have some of the softest, whitest beaches in the Carib. The water is so clear you would swear you are in a pool. Aruba is very flat (makes Ohio look mountainous) and desert like. Curacao is so close, yet so different. Kind of hilly and more tropical. Aruba is clean and friendly, Curacao is more gritty and urban feeling. That comes from the fact that Aruba has only tourism to make money on where Cuacao has shipping and oil and gas to provide jobs and income. I went diving in Aruba so I cannot talk about much more than the water (beautiful). On Curacao we went to the Seaquarium and its beach.(fun and a great beach).
Very easy to rent cars in both Aruba and Curacao, and no real reason to do so in advance. There are one or two rental companies at the pier in Aruba. Very easy to come off the ship, rent the car, and see the island. It is a great island to drive around. Leave port city and go west along the hotel/beach strand. This is very populated and looks like any Caribbean beach island. Turning to the north, the land turns more mountaineous and like a desert. Great fun on the northern beaches. In Curacao, the dockmaste called one of the car agencies and they came and picked us up. Maps not very good and we got lost a couple of times. But saw some great sights on the western end of the island. When we finished, we turned the car in at the airport, and they brought us back to the pontoon bridge downtown.
Aruba is amazing, my favourite port ever. Curacao is so-so. Beaches in Aruba are wonderful, sandy and not rocky. Try Palm Beach or Eagle Beach and I highly recommend the snorkelling tour as well. Yes, you can bargain with the cabbies and they are very friendly in Aruba but not as friendly in Curacao, from our experience. Beach in Curacao that we went to (Holiday Beach) was just OK. Both islands are very picturesque with great photo opps.
Got a local bus in Aruba, think it cost $1 US each way, and asked the bus driver to shout when we reached a nice beach. He dropped us off outside a big hotel (Wyndham I think) and beach was beautiful. Used the hotels toilets, etc.
Wouldn't bother with a taxi.