Roohafza is certainly a very cooling and refreshing drink. I dont like its taste very much, its not as delicious as rose sherbets, though people do often confuse the two. Roohafza is a blend of tastes, as can be seen in the list of ingredients along with a lot of sweetness. It can be consumed by either mixing in milk or in water.
I have enjoyed Roohafza in both forms, with milk and water. Personally, I do not like to add too much of the syrup as I find it overly sweet. I have also used it medicinally when my stomach has been too hot, and found it to be quite effective. I have also read recipes where this is recommended as a substitute for rose syrup in faloodas, ice creams, etc.; but I would suggest avoiding this since roohafza has a very distinct flavor that can really change the taste of your recipe.
Overall, though I would not recommend this as a party drink, I do feel it is a good option for home consumption, as a substitute for lime juice or sikanji, when they arent available.