Ill throw in my 2 cents
I have a macbook pro (non unibody) and while it feels pretty durable, you cannot beat the durability of thinkpads, I have lifted the things off a table by a corner of the palm rest and held them horizontal without feeling scared of breaking them.
They are known for being very durable, the screen has a metal mesh to prevent it from damage from impacts, hard drive is in a cage (magnesium I think) to protect from crushing, etc.
As for SSD/HDD most HDDs have a sudden drop protector that usually prevents them from crashing and SSDs may not actually save battery life
SSD Battery Life Hoax The price to size ratio is your own to decide, its nice to have increased performance but you can get pretty fast 7200rpm drives (a 500GB 7200rpm drive would be pretty fast due to density, my 5400rpm is awfully fast)
Also, a T400 got run over with a 26000lb truck and the memory was still intact and the battery still worked as well as the harddrive the screen obviously was cracked and the keyboard had a few buttons break.
T400 Truck