We stayed in Apartment Duje for a week. The landlady, Lydia, was absolutely lovely. She is so helpful and friendly. She greeted us when we arrived and helped us with directions to the local amenities. A really lovely lady, can't do enough to help you.
The apartments are very clean and tidy. The kitchen is well equipped with a modern cooker and large fridge. There is aircon and free wifi. The bed was extremely comfortable and there was plenty of wardrobe space and storage.
The apartment building is right on the waterfront, unfortunately our room didn't look out over the water. If you really want this, make sure you request it; it would definitely be worth it! There's a small beach to the right and plenty of beach front if you walk to the left of the apartments. The beaches are pebbly so having sandals you can swim in is handy, although not essential. The water is crystal clear and great for swimming.
There are a couple of small restaurants in Sumpetar but not a lot else to do there. We absolutely loved it as it was quiet and relaxing with lovely beaches. You can easily get the bus into Split (30 mins) or Omis (20 mins). The bus stop is right on the road outside the apartments. There are plenty of things to see and do in Split and Omis but it can be crowded and very hot, I'd recommend getting up early to make the most of it.
If you are looking for a nice place to relax and spend quality time with family or friends, you really couldn't pick anywhere better. I'd highly recommend Apartment Duje and will definitely be back.