I spent quite some time in the apple store today to compare the 15" vs the 17". I really like the look of the 17" as it is on the table, but i'm afraid that it will be too big to use it on the go. isn't it too huge to work in train or lets say at starbucks? i wouldn't move it everyday but i'd like to have it with me sometimes..... additionally, i think the 17" are looking smaller at the large desks in apple store than they would in a standard home office but i'm just so impressed by the screen and the huge real estate. would i get a similar impression and feeling by the new 15" hi-res display? Can you give me advice about how the 17-incher is usable in everyday practice?