Looks wise the keyboard is nice, but I just found that it was not so great for me when hands on.
As for the battery socket I just looked it over lightly before, but I found that looking it over more there are no metal prongs inside for the batteries to connect to. I thought it might be for the scroll LED, or the EL lighting as well, but with the lights running off the USB there is really no need for it, and this just goes to show that the battery slot has no use at all. It's just 'there', like they had an intention for it but didn't use it. ^^' Ah well.