Agree with all the comments thus far. I am a very satisfied 17" owner. Frankly, I don't find it too bulky to carry around - after several months of use, I have gotten used to the size. If you are flying coach all the time, however, then the 17" might be a problem. . .

Just a few other things. First, if you are even considering the 15", then wait. Apple is on the verge of shipping new models with a 15.4" screen and updated aluminum casing (like the 17 and 12").

The 12" PB, on the other hand, seems like nothing more then a slightly souped up iBook.