I bought the iRiver 20GB version and it is a fantastic unit. Works as advertised. The internal mike dictating capability is very good and much higher quality sound than I expected. The "usb on the go" model still isn't available in Canada and I was hot to trot.
The only operating feature that is clumsy on the 20GB model is the menu system which operatest with a joy stick kinw of button on the face. Takes a bit of getting used to. Looking at the picture of the usb capable model, it looks as if they've added buttons--better idea, I think.
I added a pair of Bose noise cancelling headphones to the mix, and, is this evere a fantastic combo for the noisy guy, where I listen to my Italian language course while I do my fitness stuff.
My old Zen Nomad 20GB is a piece of crap next to the iRiver and I wish it had broken. You were lucky Sigma!