Tiff is a very versitile format - multible images in the same file etc. The biggest problems are limited compression and the fact that there are so many flavors of it; ps uses one corel another psp still another and macromedia another - everybodies got their own idea of how to set it up. (I learned all this when I developed a small utility for Bryce users called Tiffer a while back).

If you're working on your own have and have alot of drive space Tiff can be wonderful to work with - the problem comes in  when you are working with others over limited resources.