In Island of Happiness, there were few options to use the Control Pad. Almost every action was controlled by the stylus. Some players (including me) did not care for that, but others preferred it. With the sensitivity to players' feelings that is characteristic of the creators of Harvest Moon and Rune Factory, in Sunshine Islands, the 'sequel' to Island of Happiness, a player has the option either to use the stylus or to use the Control Pad in most cases. As I 'cut my teeth' as it were on the GameBoy systems, I opt to use the Control Pad. Another reason why I tend to favour the Control Pad is the fact that my heavy use of the stylus in the early days of the DS completely destroyed the screen of my DS. It had to be replaced...
Which takes me on a slight diversion to a warning I added to some of my Guides but not all of them. Always use a screen protector on your Touchscreen. Another way to minimise the damage that the stylus causes is by using a 'pen' stylus instead of the stubby little stylus sold with the DS or DS Lite. Unfortunately, for whatever reason, these 'pens' no longer are sold. Instead, you can buy a retractable stylus, which is the same width as a regular stylus but has a telescoping feature that allows you to lengthen it. Although I find these inferior to the original 'pens', they are better than the short stylus as the amount of pressure that a player exerts tends to decrease as the length of the implement increases.
Back to the main topic now, which deals with the occasions where a stylus is preferable to the Control Pad in Sunshine Islands.
If you are playing one of the Touchscreen mini-games (Petting, Milking, Shearing), you must use the Stylus. Apart from this, however, you always have an option to choose between Control Pad and stylus. I have discovered two situations where the use of the stylus is infinitely preferable to use of the traditional Controls.
The first is when you are harvesting Crops. With the traditional Controls, you cannot reach the middle Crop in a 3 x 3 square plot in order to harvest it. If, however, you use the stylus, you CAN harvest that Crop. An early mistake of mine when I first explored Sunshine Islands was NOT to test the stylus when my Crops matured. In fact, you can create rows without breaks and harvest the middle Crops in each row using your Stylus in Sunshine Islands in the same manner as in Island of Happiness.
The second situation is when you are giving a Gift to some one. If you use the Control Pad, you run the risk of dropping the item, becoming guilty of a littering offence. That will please the Witch Princess enormously but has more disadvantages than advantages in that it will upset other Characters, decreasing their Friendship and essentially waste the item. If you use the Stylus, however, you can give an item from some distance, rather than being forced to stand directly next to him/her. This is particularly useful when you are interacting with the tiny Harvest Sprites on Sprite Island as they tend to zip about the Island at incredible speeds.
You actually can perform your 'meeting and greeting' ritual with all Characters using your Stylus, which will save time as you can 'call out' to them from a distance and they will acknowledge your greeting in the same fashion as if you were next to them.
If use of the Stylus is so more advantageous to a player, why on earth do any of us use the Control Pad instead. The answer rests partly upon personal preference but partly on a dislike of using the Stylus for movement in general. Once I begin to use the Control Pad, I tend to stay with it and must force myself to remember that the Stylus should be used for certain actions. There are cases when the Control Pad actually works better for me. I do believe that the Control Pad is easier to use when 'charging' a Tool, for example.