While I don't know much about the devices you listed, most people on here think hard drives are good but flash media is the better choice. There are different devices like the iriver H120 that has a hard drive but I've never heard of anyone stating it locks up that frequently--but I'm not a know it all, I'm sure it can happen. There is software for the irivers called rockbox that allows the hard drive not to spin up as much for longer recordings which I have installed on my iriver h120.
The companies that continue to make hard drive based recorders (i.e. sound devices) probably make them to last a little longer than 1st and 2nd generation ipods with hard drives since these recorders are a little pretty expensive.
Perhaps if you don't want to worry about lock up on hard drives, invest in a CF kind of recorder--R-09/HR, zoom H2/4, Fostex FR-2LE. I also think people have stated the sound devices allow for CF cards--in addition to a hard drive.
I hope someone can second my comments here and maybe even approve/disapprove of what I said in order for me to learn more.