We've pretty much done it all, from not renting anything to renting scooters to renting jeeps to renting cars. We've rented for 2 days, 3 days, 1/2 the trip and for entire trips. This last visit it was a car for 3 days. We got the car on day 2 and got what groceries we needed from the store that lasted us the rest of the week and used the car to get around the island and eat at a few distant restaurants and hit downtown.
When we don't have our own mode of transportation, we use taxis and have never had to wait more than 5 minutes. I really think DH likes not having to drive; I've driven myself to town and back, but also enjoy being picked up and dropped off. After our first trip to Aruba when we used the "included" hotel transportation, which was a bus and we were the last stop, hubby won't get on a bus. LOL
Our first trip we rented a car for 2 or 3 days to do some exploring on our own. Being our honeymoon it was just the 2 of us. We have rented a car every trip since as we usually travel in large groups. Two years ago I rented a Hyundai 12 passenger van. That was perfect!
We will rent a car for Christmas for a week. Being there for two weeks, it gives us an escape from the beach.
Otherwise, we do not rent-- no drinking and driving (at Christmas we have a designated driver), no getting lost and no worries of car break ins. Last trip as well as many others since 2006 we were perfectly happy to leave the driving to Bully.
Mangel Halto for snorkeling, Palm and Arashi for beach time.
When we went to Aruba in May 2012 we did not rent a car. I was uncomfortable about driving a car that wasn't mine in a place I did't know. Se we relied on buses when we went to Arashi and Oranjestad, and taxis when going to certain restaurants.
But last May I went to Orlando with my wife, and anyone who has been there knows how important it is to rent a car. So I had to overcome my fears and everything went very, very well. I guess that my next trip to Aruba will include a car rent.