trainguy77 said:
Yes I have been thinking about this for awhile. I will be buying a laptop later this year and I want a 17" because it will be my only computer however I would be bringing it to school everyday. So it may get to big. But I have a big backpack so that may not be a problem.

I don't know which to go for. At least I have a couple months to decide.
I am in your situation, currently...Perhaps I can offer some advice based on my experience:
I'm a grad student and I own a 17" PB and a few desktop PC's at home; however, the PB is my main computer because it's *all* I ever use. I bring it to my office everyday and, up until very recently (I've had it for near on 6mos. now), I haven't found it to be an issue. The weight (for me, at least) is a non-issue...It's light and thin; that's all that counts. The screen real estate is amazing...i mean, amazing!

Safari, iChat, iTunes, Sherlock, TeXShop, and Matlab all on one screen with very little overlap allows me to work faster and more efficiently than I ever did on my old 15" Sony laptop.
Having said that, I have recently become enamored by the concept of a very portable, all-in-one computer. I'm a huge fan and daily user of the Apple Newton and I'm a huge supporter/fan of tablet pc's in general (and an Apple iTablet, specifically). Since the Newton is not powerful enough to be a stand alone and there *is no* iTablet, I've begun to eye my officemates' 12" and 15" PB's.
The screen size is a huge perk on the 17", but I tend to want to bring the lappy to more places nowadays (previously the Sony was essentially stationary) and as such, I feel sort of handicapped by its large size. It's more than a little cumbersome to place on your lap or desktop in a typical library study cubical or while sitting outside to simultaneously enjoy the great weather and be productive (more the former than latter

).
I've had a lot of time to fiddle with the 15" MBP, so I already have formulated my opinion on that size. So, now I'm anxiously awaiting the arrival of the new pro-level model of the 13.3" MacBook and the 17" flagship MBP (just in case

). Sorry for the long post, but I figured it might help you or others a bit...
Regarding the OP: Wow!

that's a monster of the laptop...My limit is definitely 17...