Should icon designers use bitmaps or Vector Graphics when creating icon sets?

Doing some research about all the different topics related to design, specifically icon design, I read a lot about the two most common icon formats: Bitmaps and Vector Graphics. Bitmap is an image file format which stores in an array the color information for each pixel. This type of images have a fixed resolution and resizing causes quality lost. File sizes of bitmap images tend to be quite big compared to vector size, that's why they are usually compressed, causing us to sacrifice quality in order to get a lower size of the file. On the other hand, Vector Graphics are images composed by points, lines and primitive shapes, also known as paths, which can be filled by colors or patterns. Differently from Bitmaps, information of how should the image must be drawn is stored when a Vector Graphic is created, instead of how should it look. When working with Vector Graphics we find several qualities such as, lower size of files and better quality of images. We can also re size our graphics and have the exact same quality we had in the resolution we created it, unlike bitmaps, which tend to loose quality and blur when we scale them. So, if Vector Graphics work so well, why are there still professionals who rather create they're icons in a bitmap format? Bitmaps are a great way to represent pictures, in a way Vector Graphics never will. Every single pixel has a characteristic, letting us have a more realistic look (our photographs will always be a bitmap, there's no way we can convert them into a Vector Graphic and get the realistic look, on the contrary, Vector Graphics can become bitmaps easily). Nevertheless, Vector Graphics are a more accurate way to represent icons or logos, or at least that's what I thought. Some experienced designers think bitmaps should be the standard when it comes to create icons, however, here at iconshock, we believe it's possible to create excellent icons using Vector Images. Yet, opinions I found concerning this subject are obsolete. Back in April 2006, Firewheel Design published a very interesting blog entry where they explain that the biggest weakness of Vector Graphics resides in the creation of small icons. Apparently, when you reach a certain size limit, your monitor does no longer display the icon correctly, since monitors are a pixel based displays. The question is, is it worth to redraw icons in every single needed size as bitmaps, or is the result from scaling Vector Graphics good enough? Has this changed in the last couple of years? Have you noticed any improvement when it comes to Vector Graphics, or do you think they have remained the same? Another similar opinion, but with different arguments caught my attention. For this designer, the capability that bitmaps offer us to display more details and personalize our icons makes them a better solution than Vectors. I don't agree with this, since icons are supposed to keep it simple and at the same time show every relevant detail that wants to me transmitted. Vector Graphics are perfectly capable of doing so, it all depends of the designer skills. Results achieved from Vector Graphics, compared to the ones achieved from bitmaps, not only allows the final customer to experience a better quality for their products, but also represents savings in terms of time and money. What do you prefer? What are your opinions on this subject?