If you think it's too heravy, then get a smaller one. However, 17" is a lot of real esate. Before I switched back to desktop, I was purely a laptop man, going form laptop to laptop. Then I got three monitors, and never looked backed. However, I still use my 15" laptop when I am not at my desk and it is quite helpful.
My recommendation? Again, if it's too heavy for you, then get a smaller one. But if nothing is wrong with it, the more real estate the better!