I must tell you, I'm getting pretty tired getting on and off this bandwagon. I'm referring to the flash verses rotating media bandwagon, when it comes to MP3 players. I teetered on the edge for a while, weighing the huge capacities of rotating media verses the ruggedness of flash.
As the flash prices continued to drop, the line marking where it's more cost-effective to go with a rotating hard drive began to blur, moving up to the 10-Gbyte range. In my case, conventional thinking won out (over form factor)20 Gbytes for under $200. Every CD that I care about fit into that space. It was a no brainer for me.
Then the seemingly impossible happened: while on the treadmill with my player, the hard drive crashed. So it ain't so! I can still see my friend Arie Tal of M-Systems saying "I told you so."
I managed to get the disk spinning again, but I won't be using the player on the treadmill, or for any other turbulent activities. The moral of the story, at least in my case, is that if you're going to use the MP3 player in stationary environments, rotating is fine. But in the car (or on the treadmill), go with flash.