A few observations on the different models:
- Upgrading the 17" model was easier. (Partly because I've done it once before, and partly because it's generally a more accessible machine.)
- The screw patterns are identical. However, the Phillips screws inside the battery cover are far more accessible than on the 15" model; they're angled so you can get a screwdriver to them without contorting your hand.
- The lid seems to crack off of a 17" model with greater ease - less fiddly plastic interlocking.
- There's more use of sticky tape inside a 17" machine!
- The nubs that hold the drive in the laptop chassis are different on the 17", asymmetrical in design. I wonder why the two models differ like this?