To me an immersion blender is akin to food processors. While they are not an absolute necessity in food preparation, what they are capable of doing is nothing short of miraculous. This appliance, much like a food processor, will have you preparing foods much easier than before, but they will also have you preparing foods with better textures. Mine is used so very often. Besides the ease of blending soups right in the pot, these amazing stick blenders emulsify sauces and salad dressings like a dream. I've tried the Braun brand, the Williams Sonoma brand (sold at their store), and one called Bamix. On the web I researched Bamix quite a bit, and this is the one I opted for. It is made by a Swiss company which has a very long history of making this particular stick blender. I ended up getting mine at Sur La Table. You could drive yourself crazy, obsessing about the various brands, as there are so many. I am deleriously happy with my Bamix!
I think it really depends on what kind of cooking you do (as does any other appliance purchase) and what you already have. I got one with all the attachments for Xmas and actually exchanged it for one that doesn't because I already have two food processors.
I wanted it because I love to make blended soups and doing it in a food processor or blender is always such a messy hassle. It's a dream for that, and there's a lot more soup being eaten in my house!
Unless you know you're going to be doing a lot of heavy-duty blending with it, the bottom of the line models seem to be perfectly fine.
It really is. I think it's worth spending the extra $10 and getting one with several attachments. Ihave a braun that has the immersion blender part, a small blender container and a whisk. I actually use the blender compartment and the whisk more than the blender attachment!
Here's what I mainly use each for:
pureeing soups, cooked veg (eg. spinach for saag)
whisk: meringues, creaming butter and sugar, beating eggs and sugar for cakes
herb chopping compartment:
coarsely chopping nuts, pesto, grinding whole spices.
It's a nuisance when I have to liquify a large quantity of something, as I need to do it in batches. I also find that if I really fill it up, I will need to mix the contents with a teaspoon halfway through blitzing, because the stuff at the bottom liquifies/pulverizes, but the leaves/spices/stuff at the top doesn't.
Mine is a Braun, and it's easy to clean and store. However, my mum's Braun immersion blender stick warped a little because she plunged it into boiling soup and the plastic softened. I've seen ones with metal attachments instead of plastic, which might solve this problem. Otherwise, just wait for the soup to cool down, like I do.
IMO the stick blender is totally worth it. I have a Braun w/attachements (but no wisk). the three major advantages are it's versatility, ease of use and the clean-up is a breeze. if you have a subscription to cook's illustrated then you can look at their comparsion/test under the "equipment corner" tab. when there, look for the small appliances index to find 'blenders, immersion'. if you don't have a subscription, let me know and i'll paraphrase their results to you. this said, the results are from 1993 so you might want to do a search on this board as i remember there being several recent discussions about immersion blenders/blender sticks.