Remember guys, this is just like buying a mini TFT Monitor, therefore the quality of the panels is vastly going to vary. Go and look at them in a store, then order online. Another thing to bare in mind is the software that they come with and how 'userfriendly' the GUI is!
I think there a great idea, some you can select a folder on your PC and it will stream all the photographs from that folder to the device, some you have to upload them to, some you have to stick a memory card in. Either way, there a good idea, you just have to be selective!
Greg