Stayed in Haikou Hotel for 2 nights with intention of staying another 3 nights after my Sanya trip. Decided against it. Room is smelly and not so clean. That really put us off. Cleanliness is most important to me. Location is good. Near shopping centres and eateries.

Haikou Hotel is an old hotel with 196 rooms in two connected buildings, rated 4 stars in the past, but now maybe 2-3 stars compared to new hotels. Taxi from airport to hotel was around CNY50. Small hotel entrance was not easy to find, since it was next to a big nightclub (see photo).
Hotel location is excellent, at the junction of Haifu Ave and Haixiu Ave, both are shopping/entertainment roads. Turning right from hotel entrance and walking 500 meters into Haifu Ave, there was a big mall with Carrefour supermarket. There was a popular conveyor-belt sushi restaurant just outside Carrefour. The more adventurous shopper should cross the overhead pedestrian bridge at Haifu and walk towards the Bank of China. Behind was a network of alleys with hundreds of shops, selling wholesale stuff like clothing, shoes, bags, etc. Turning left from hotel entrance towards Haixu Ave, there were upmarket shops. About a block away from hotel was a restaurant selling Singapore-style pork rib soup (bak kut teh) and chicken rice. About 200 meters away from hotel was the Ming Chu supermarket.
The bell desk was on hotel 1F, together with a big shop Meiyu International Pearl City. Up on 2F were the hotel reception, business center, restaurant. We got a room on 4F for CNY278/night net (without breakfast, booked through hotel website), with window looking into the dark alley behind hotel where the Crossing Bar had a side entrance.
Hotel room had twin beds, with pillow and bolster (the first I had seen in hotels), and individual airconditioner. There was kettle with tea bags, but no free bottle water. The 20” TV was old; there was no refrigerator, no hairdryer, no tissue box. On the first day, bath towels had holes in them. There was free LAN internet at the work table. There was a sliding glass door between the bathroom’s shower booth and the bedroom. As a result of water coming out into the bedroom, there were water stains on wall, paint peeling off, floor tiles in bedroom popping up, and the wood skirting had fallen off. If you can ignore all these defects, and only want a central location and a good sleep for USD40/night, this hotel is OK.
An alternative hotel on Haixiu Ave is the 4-star Hainan Xinyuan Hot Spring Hotel (CNY310).
All the Hawaii-type beach action takes place in Sanya at the south tip of Hainan island. Haikou at the north tip is the government and commercial center. It is a good base for exploring the northern part of the island, and for buying Hainan native products like dried seafood, coconut-based food and candy, and coffee. One touristy-thing not to be missed is the Impression Hainan show at Holiday Beach. This show was designed by famous movie-director Zhang Yimou, who also did the ceremonies at Beijing Olympics and Guangzhou Asian Games. Recommend that you take this show as part of the Haikou night tour (CNY218) which can be booked at the tour desk. It was really troublesome getting back from Holiday Beach by taxi at night.