A hand blender allows much more ease of use.Add a juicer and you can have all that a traditional mixie offers, without the problems of weight and storage. Soups, shakes, smoothies, chutneys, whipped butter, eggs, potatoes or cream and more may all be turned out in minutes.
A hand blender however has small capacity and power. So it cannot powder sugar or grind dal for idlis and dosas because they are just too hard. Also, you need to be careful to keep the blade immersed in the solid/liquid item being blended/pureed/chopped to avoid it from spilling on your walls and shelves. One cannot use it for more than one minute at a stretch or it might get overheated, and it needs a couple of minutes' break in between.