Powersaves isn't hacking really. It just allows you to max your bank, and in the first five slots spawn items. But each slot is reserved for an item type i.e. you can only spawn furniture in one slot and wallpaper in another, and you have to enter the game each time to move the item or it will just keep replacing the item.
hacking, has several tools. you can input any villager you want {obtain all your dreamies}, use a map editor to change your map, change grass shape, design your town in amazing ways, and use a hex editor even to change your town name, villager gender etc.
HOWEVER the DS supported firmwares: all 9.x, up to 9.5.0-22 (except 9.5.0-12). If your DS is past that it is impossible to hack. If you can it's better to have powersave backups and then just use the proper hacking tools, as they can get you insects, and all rare items unlike the powersaves!