I took a 4D/3N package to Langkawi (with stayover in KL allowed) and extended 3D stay in KL with husband + 2 kids (5+2). We had a great time. Here is how my days were spent:-
Day 1: A.M. catch MH flight from HK for KL, Wait 3.5 hrs for flight to Langkawi. Arrive Langkawi around 6pm. Stay in Pelangi Resort (bungalow type)
Day 2: Swim in pool/sea at resort; Car hire and take a drive to the island to see the Eagle Sq. at night
Day 3: More sun-bathing. Drive to see the island (or can join local tour)
Day 4: Take 1-hr flight to KL. After check-in, go to KLCC, twin towers for sight seeing/shopping in town. Stay in Palace of the Golden Horses hotel (but far away from city centre).
Day 5: Check in to Sunway Lagoon Hotel Go to Genting Highlands with local friends and spent the day in Theme Park with kids. Come back to KL in the evening. Some people may like to stay over night in one of the hotels there instead.
Day 6: Spend the day in Sunway Lagoon Theme Park (open from 11am to 6pm). There is wet park and dry park. To join both. Adult RM36, Kids >3 RM29. This is a smaller version of the Lost City in South Africa if you have been.
Day 7: More Swimming in the pool. Shopping for souvenirs at the Pyramid shopping centre. Then catch flight at 6:45pm for HK.
My 2 kids love this vacation. Besides taking medicine, I did not need to bring a lot of other stuff. We all eat and drink (their water) at the hotel. There was no problem. Toilet wise, they are better than some in HK because of lower user frequency.
They have Watson's and Guardian chemist in big shopping centre. You will find their merchandise a lot cheaper than in HK. Even baby milk (formula) is 40% cheaper. There are many chemical/pharmaceutical companies in Malaysia. I even bought half a dozen Hydrocortisone
cream (for Eczema) at RM 5 (HK$11) at the chemist. They are sold for HK$35 in HK.
Even though it was not the sale season there, you will still find summer clothes/shoes a lot cheaper than in HK. Of course, not the brand name stuff. I bought a lot of hair clips and accessories for the kids. Varieties is large and they are even cheaper than stuff you get from Mongkok or Ladies Market.