What are the advantages of a quad processor leaving aside multitasking?
Unless you are doing really processor intensive work (Or get a really good deal on a quad core system) A Quad Core chip is still overkill in my opinion
There are still few applications that really take advantage of multi core chips, so the advantage is limited. Some games, video editing, graphics or processor intensive applications do benefit from dual or quad processors, provided those applications support multi-processors.
I have a core2duo, dual core processor, see signature, but for the most part it is virtually idle. So I don’t get the full benefit but I wouldn’t go back to a single core.
As Mac said if you get a good deal yes but I wouldn’t get it just because it has a quad core, but because of the work that I do (cpu intensive) and the applications supported it, or 3 cores could be virtually idle and that isn’t value for money.