Yes, rhowaldt, because you should usually, after each use, clean the pipe and then put it away for a day so that it can dry out. Some tobaccos leave condensate, so you need a few more in rotation.
About the differences in pipes: good question! Apart from the material used, they "smoke" differently (as in draught), they have different bowl sizes (some of them can be smoked for several hours) and there are versions with filter (e.g. 6mm, 9mm) or without filter. There are different shapes, like Billiard, Dublin, Canadian, Bent, Half-Bent, Churchwarden, ... too many to mention. Even the mouthpieces can be shaped differently, have different materials and behave differently - which also depends on the tobacco you smoke. The great thing about pipe smoking is that you learn how tobaccos differ, experience different tastes (I mean the non-aromatic, natural tobaccos) and it is a nice lesson for the tastebuds. I never knew that Virginia is a slightly sweet tobacco, and that the so-called Turkish or Oriental tobaccos have a quite typical, strong smell. Smoking cigarettes (after smoking pipes) is like a guessing game ("Which kind of tobacco is used there?")
As I said before, smoking pipes has taught me to respect the tobacco. You can't (or won't) smoke a pipe in a hurry. Choosing the right pipe, and tobacco, packing it, sitting back and enjoy the flavours, this cannot be done on the way to the bus station. It is a quite cost-efficient way of smoking (although pipe tobacco is not cheap) - you need less and can smoke for an hour or more.
Enough of this babble
VLL! 
Nothing right in the left brain. Nothing left in the right brain.