I was really nervous about the move when I bought my EII+ a few weeks back. Luckily I bought it from a friend who lives in my city so it didn't have to be shipped. I put a hard-shell keyboard across the seats of my van and put the EII on top of it so that the body wouldn't flex (a problem). The EII survived the move and doesn't have any problems, I am glad to say.
I have heard that EII memory can decay or get "holes" in it. The samples will still play but have dropouts I guess.
Also concerning bad disks - I found that bad disks sometimes would read after 10-15 tries. Then I would immediately save the bank to a new disk. So if you are interested in preserving the disks don't give up and toss them until you are absolutely sure they won't read. I may have junked a disk or 2 before I found this out.