I don't think any 17" laptop owner would argue, they are exponentially heavier than 15". I was constantly shifting from arm to arm carrying it long distances. It's even hard to fit under an airplane seat or even on the fold down table. I would have gladly traded mine in for a 15" at the time. I even considered buying the 13" Macbook Air as a second portable laptop. With internal optic or CD drive and a ridiculous price tag, I quickly came to my senses.
The mat screen version of the Macbook has no glass, but it's got lots of metal
The 15" Macbook Pro seemed much lighter than the Sony Vaio. Maybe it's the lack of glass and smaller profile of the Mac?