Actually there isn't any said term that gives one model a certain lid over another..... Yes, the Z35 has a plastic lid.... and chassis...... just like all of the other current Z models (Z62/Z96)...... This doesn't go for last years Z models that mainly came as barebone systems off what were ensemble (complete) models.....

But for Jumper - the M5 (Z33) lid is magnesium.... same as the S5, V6, W7.... What's funny is that the W5 uses a carbon fiber lid... it's the only S/W/V/R lid that isn't a metal........ while the W1/W2/W3 all have the anodized brushed aluminum lids.

In terms of hard drive protection.... there is some built into the hard drives, like Hitachi and Seagate in terms of a fuild shock..... and all of the systems have a rubber hdd isolator under the hard drive covers which help a lot. Nothing is going to help a 3 foot drop, except for maybe a little prayer and a dash of hope. If the system is writing to the hard drive when it drops, you're about out of luck... but if it's in standby or off, you'll have a great chance that damage wasn't done. By default, Asus systems anyway automatically go into standby when you close the lid.... and that would obviously also be the best way to travel from one point over to another anyway..